Air Wave--All of Air Wave's 1940s stories are in. After his series ended, he migrated to Earth-1, apparently with a brother as well. Air Wave became father to the second Air Wave while his brother would become brother to Green Lantern Hal Jordan. Though his modern day stories after the 1940s took place on Earth-1 (including adventures with Superboy), he still also appeared in flashbacks to Earth-2. The story behind his migration was never told. The last appearance of the Earth-2 Air Wave was in All-Star Squadron # 60, August 1986. Any appearances of Air Wave I after that were on Earth-Post Crisis, New Earth-0, the DCnU, or some other reality within the multiverse.
Alfred--Alfred was a member of the Batman supporting cast who got his own spin-off. See Batman below.
All-Star Squadron--The entirety of All-Star Squadron up to issue # 60 is in Earth-2. This series began in the 1980s, created by Roy Thomas, but occurred in the 1940s. In issue # 60, the after effects of the Crisis on Infinite Earths took effect, thus the last couple of pages actually take place in Earth-Post Crisis, which is the team's first post-crisis appearance.
Aquaman--Up until All-Star Squadron, it was believed that there was no Earth-2 Aquaman, and that Aquaman's golden age stories were part of Earth-1 continuity, with exception to his original origin, which was retconned in the Silver Age. But in All-Star Squadron, Roy Thomas revealed that there was indeed an Earth-2 Aquaman, thus his 1940s stories took place there. The dividing line to separate where the Earth-2 adventures end and the Earth-1 adventures begin can be debatable. Some like to create one single line for all the DC characters of the 1950s, making Earth-1 start either at November 1955 (the first appearance of the Martian Manhunter), September 1956 (the first appearance of the Earth-1 Flash, or even February 1960 (introduction of the Justice League of America.) But these are really not considering the stories. And then there are those who would place all 1950s stories on Earth-E. Mike Voiles comes up with the best explanation I've found here.
Arak--Some think this character was from Earth-2, on the basis that his only appearance outside his own series was in All-Star Squadron, but this was a Crisis crossover in which heroes were gathered from various times and realities, so he may be from Earth-1.
Arion--Clearly from Earth-1, but mentioned here since post-crisis he pretends to be Power Girl's grandfather.
Atom--The Atom of Earth-2 had his main career in his own series, which ran in the 1940s, and as a member of the JSA up until 1951. In 1961, a new Atom appeared, who existed on Earth-1, but the Earth-2 Atom returned as a member of the Justice Society, appearing frequently as a guest in the pages of Justice League of America and later in the 1970s and 1980s in All-Star Comics and Adventure Comics. His final Earth-2 appearance was in All-Star Squadron # 60, August 1986. Following that, any appearances of the Golden Age Atom were his Post-Crisis counterpart. On Earth-1, the Atom is Ray Palmer and a member of the Justice League of America, whose first appearances was Showcase # 34, September 1961.
Batman--This will also cover Alfred and Robin. Batman's Earth-2 tales began in 1939. Where they ended is debatable. Some would end them with December 1949 (end of the 1940s), March 1951 (last JSA story), October 1955, August 1956, December 1959, January 1960, or even April 1964 (last appearance of the old costume). None of these factor in the actual stories to compare the mythologies of the Earth-1 and Earth-2 incarnations. However, good ol' Mike Voiles again has presented his case, which is
here. So this would place his last golden age Earth-2 story as Detective Comics # 220, June 1955. He would return in the Silver Age, having retired. Robin would be still active with the JSA, and he would have a daughter, the Huntress. Bruce Wayne of Earth-2 would become Gotham's next police commissioner, and then be killed in Adventure Comics # 462, March 1979. He would continue to appear in flashbacks though, until his final Earth-2 appearance in Secret Origins # 6, September 1986. Following that, the Earth-1 Batman would only appear one more month, in October 1986, after which the only Batman that would be soon from November 1986 onward would be the Post Crisis version.
Black Canary--This one is interesting. Black Canary of Earth-2 first appeared in 1947 as a supporting cast member of Johnny Thunder who soon stole the series and even his membership in the Justice Society. Then she said farewell when the JSA ended in All-Star Comics # 57, March 1951. She resurfaced with the rest of the JSA in the 1960s, but in 1969 it appeared she migrated to Earth-1, only she didn't. In the 1980s, a story would reveal that the Black Canary we saw as a member of the Justice League and lover of Green Arrow was actually Black Canary's daughter!!! Apparently a switcharoo was made behind the scenes of a JLA tale in 1969, and even the daughter thought she was her own mother, having gotten her memories. The Earth-2 Black Canary's real last appearance was in Justice League of American # 220, November 1983. Post Crisis the relationship of the two Canaries was different.
Black Condor--Black Condor is a Quality character, but as revealed by Roy Thomas, he began on Earth 2 and migrated to Earth-X. The migration occurred in All-Star Squadron # 50, which takes place between Crack Comics # 25 - 26. Black Condor's final pre-crisis appearance was Crisis on Infinite Earths # 12.
Blackhawk--Blackhawk and his team were published by Quality, but as revealed by Roy Thomas in All-Star Squadron, the team was from Earth-2, but then migrated to Earth-X in 1942. He apparently died in an untold story prior to the 1970s. His final Earth-2/X appearance was All-Star Squadron # 50. The transition from Earth-2 to Earth-X happened in All-Star Squadron # 48 to 50, which takes place between Military Comics # 12 and 13. There was also an Earth-1 Blackhawk, who first appeared in Blackhawk # 108, January 1957.
Black Pirate--One of the few historical heroes from Earth-2, allegedly, since his stories were published in the 1940s, but his appearance in Justice League of America might argue that he was from Earth-1.
Boy Commandos--These kids who fought in World War II had a series in the 1940s, which were made clearly to be part of Earth-2 when they crossed with the Sandman and the Newsboy Legion. The problem though is that one of the Commandos, Brooklyn, later became Terrible Dan Turpin, a cop in Metropolis, on Earth-1, while still having been a member of the Boy Commandos as a kid!!! Apparently Brooklyn had been part of the great migration that happened in the 1950s. But why did these heroes migrate? And who migrated? Well, it seems the migraters were Air Wave and his brother, Sargon, the Guardian, the Newsboy Legion, Brooklyn, and Zatara. (Steel also migrated but his was explained and shown to be a solo migration.) I'm guessing that the migration had something to do with the House Un-American Act which shut down the JSA and super-hero activity in general, a need for these heroes to further adventure, and a discovery of a new alternate reality with no heroes (yet). Perhaps it involved the Crisis, which affected more than one time period. The last appearance of the Boy Commandos of Earth -2 was in Boy Commandos # 36, December 1949. Any appearance after that was their post crisis counterparts. As for Brooklyn, I'm unclear of his final pre-crisis appearance, but (despite being from Earth-2), he was part of the Earth-1 Superman and New Gods continuity, and thus his last appearance couldn't be after September 1986, since October 1986 was the great reboot of Superman (and thus the New Gods as well) for the Post Crisis Universe.
Bulletman--Bulletman operated in the golden age, but on Earth-S. Post Crisis he would be part of the All-Star Squadron.
Captain Marvel--Captain Marvel lived on Earth-S, but he did visit Earth-2 in 1942.
Captain Marvel Junior--Captain Marvel Junior lived on Earth-S, but he did visit Earth-2 in 1942.
Captain Triumph--Captain Triumph was a Quality character. We can presume that he began his career on Earth-2, because he appeared on the cover of All-Star Squadron # 1, though he never actually appeared in any stories. (Basically, he was considered a candidate for the team, but never participated.) Since he was a Quality character, it's assumed he migrated to Earth-X, though this was never shown and he never crossed with any other characters. He likely migrated after All-Star Squadron # 50, and between Crack Comics # 27 and # 28. His final pre-crisis appearance was Crack Comics # 62, September 1949.
Catwoman--See Batman.
Congo Bill--Though this character debuted in the golden age, he has no ties to Earth-2, and in fact all evidence points to him existing on Earth-1. He has appeared in Superman's Pal Jimmy Olsen and was a member of the Forgotten Heroes on Earth-1.
Crimson Avenger--The Crimson Avenger's tales take place on Earth-2 in the 1940s. Following his final golden age appearance in Leading Comics # 14, Spring 1945, he and his fellow members of the Seven Soldiers of Victory were hurtled through time, to be rescued by the JLA and JSA in the 1970s, pulling them forward to that time period. The Crimson Avenger died in DC Comics Presents # 38, October 1981. His final Earth-2 appearance was in Secret Origins # 7, October 1986. Any appearance after this would be his post crisis counterpart. It should be noted that there was an Earth-1 counterpart of the Crimson Avenger, whose career was never chronicled, but he had a successor who appeared in a silver age issue of World's Finest.
Doctor Fate--Doctor Fate's tales from 1940 to 1951 take place on Earth-2. He then returned in the 1960s with the rest of the Justice Society, still living on Earth-2. His final Earth-2 appearance was Infinity, Inc. # 30, September 1986. All appearances after that are his post crisis counterpart. His first post crisis appearance was Legends # 4, February 1987.
Doctor Mid-Nite--Doctor Mid-Nite's tales were all Earth-2 as well. His own series was in the 1940s but he also appeared with the JSA up until the 1980s. His final Earth-2 appearance was Secret Origins # 7, October 1986.
Doctor Occult--All of Doctor Occult's pre-crisis appearances are on Earth-2, but it wasn't until All-Star Squadron that it was revealed that Doctor Occult existed on Earth-2. Oh sure, we do have the assumption that all golden age DC is Earth-2, but from a crossover/shared reality stand point, there had been no evidence that this hero was part of Earth-2 until the 1980s. His final Earth-2 appearance was All-Star Squadron # 60. His first post crisis appearance was Young All-Stars # 3, August 1987.
Doll Man--This was another Quality character that Roy Thomas retroactively placed on Earth-2. The character migrated to Earth-X in All-Star Squadron # 50, which takes place between Feature Comics # 61 and # 62. His final pre-crisis appearance was Secret Origins # 8.
Firebrand--This was another Quality character that Roy Thomas retroactively placed on Earth-2. The character migrated to Earth-X in Justice League of America # 193 and All-Star Squadron # 1 - 50, which takes place after Police Comics # 13 and is his final chronological appearance. His final pre-crisis appearance is Crisis on Infinite Earths # 9.
Flash--Jay Garrick was the Flash of Earth-2. His series was published in the 1940s and he appeared with the JSA up to 1951. He was the first hero of Earth-2 to appear in an Earth-1 story, and that crossover was the start of the DC Multiverse concept. Jay's final Earth-2 appearance was Secret Origins # 9, December 1986. Following that, Jay's appearances were of the first Flash of Earth-Post Crisis. The Flash of Earth-1 was Barry Allen, a member of the Justice League of America, whose first appearance was Showcase # 4, September 1956.
Freedom Fighters--This was a team that mainly consisted of Quality characters, who had migrated from Earth-2 to Earth-X in 1942. The initial roster though was a mix of Earth-2 and Earth-X characters. The team's migration occurred in All-Star Squadron # 32 - 50 (the origin and earliest chronological appearance), which occurs before Justice League of America # 107, their first published story. Their final pre-crisis appearance was Crisis on Infinite Earths # 9.
Gay Ghost--Later renamed the Grim Ghost in reprints when suddenly Gay had a different meaning. He never really had any crossovers in the golden age so his only evidence of being in Earth-2 is his appearance in Who's Who, I suppose. His final pre-crisis appearance was Sensation Comics # 38, February 1945.
Ghost Patrol--Another one who was on Earth-2, but never interacted with other Earth-2 characters. Their final Earth-2 appearance was Flash Comics # 104, February 1949.
Green Arrow--Green Arrow started off as a character in the 1940s who existed on Earth-2. He is one of those characters whose series didn't end during the transition from Earth-2 to Earth-1.
Once again, I defer to Mike Voiles to find the dividing line. After his final golden age tale in World's Finest # 93, March 1958, he was tossed back in time with the rest of the Seven Soldiers of Victory. Note that the time tossing tale happens in the late 1940s, so that means all the stories up to 1958 have to have happened before that late 1940s story. He was rescued and brought forward to the 1970s by the JLA and JSA. His final Earth-2 story was All-Star Squadron # 60, though he actually died in Crisis on Infinite Earths.
Green Lantern--Alan Scott was the Green Lantern of Earth-2. He actually got his powers from a lantern that was forged from the Starheart, an object of concentrated magic that Earth-1's Guardians of the Universe banished from their reality, sending it to Earth-2. Alan Scott's adventures took place in the 1940s and he was a member of the Justice Society of America and All-Star Squadron. He retired in 1951, but operated occasionally in the 1950s, as seen in Superman Family. He came out of retirement in 1962. His final pre-crisis appearance was in All-Star Squadron # 60. Alan Scott's appearances after that are the golden age Green Lantern of Earth-Post Crisis. The Earth-1 Green Lantern was Hal Jordan of the Green Lantern Corps and Justice League of America. His first appearance was Showcase # 22, September 1959. Interestingly, Hal Jordan's father must come from Earth-2 originally and was part of the Great Migration. This is because Hal Jordan is the nephew of Air Wave I, who is from Earth-2. Alan Scott's first post-crisis appearance is Infinity Inc # 33, December 1986.
Hawkman--Carter Hall was the Hawkman of Earth-2. He operated in the 1940s with the JSA and All-Stars. He retired in 1951 but came back in 1962. His final Earth-2 appearance was All-Star Squadron # 60. On Earth-1, Kator Hol is from Thanagar but comes to Earth to become Hawkman of the Justice League of America and assumes the civilian identity of Carter Hall. His first appearance was Brave and the Bold # 34, February 1961. Carter Hall's first post-crisis appearance was All-Star Squadron # 60, August 1986.
Hop Harrigan--This character exists on Earth-2, as evidenced by his crossover with the JSA. He operated in the 1940s. His final Earth-2 appearance was All-American Comics # 99, July 1948.
Hourman--Hourman was a member of the JSA, All-Star Squadron, and the Freedom Fighters, though he didn't migrate to Earth-X with the rest of the Freedom Fighters. Hourman's final Earth-2 appearance was All-Star Squadron # 60. Hourman's first post-crisis appearance was All-Star Squadron # 60, August 1986.
Human Bomb--This was a Quality character who started on Earth-2 but migrated to Earth-X in All-Star Squadron # 50, which takes place between Police Comics # 12 and 13. His final pre-crisis appearance was Crisis on Infinite Earths # 12.
Huntress--The Huntress was the daughter of Earth-2's Batman and Catwoman. She was a member of the 1970s/1980s Justice Society of America (aka the Super Squad). She also had her own back up feature in Wonder Woman. She died during the Crisis on Infinite Earths. Her final Earth-2 appearance was Infinity Inc. # 24.
Ibis--Ibis was from Earth-S, though post-crisis he was retroactively made a member of the All-Star Squadron.
Infinity Inc.--This was one of the few series set on Earth-2 but occurring after the golden age. This team is the children of the JSA. Their final Earth-2 appearance was Secret Origins # 9. Following that, the series continued featuring the post-crisis Infinity Inc. Infinity Inc's first post-crisis appearance was Infinity Inc # 33, December 1986.
Invisible Hood--This is a Quality character who didn't make it to Earth-X for very long. He died as part of the original line-up of the Freedom Fighters. His death was shown in All-Star Squadron # 31 - 32, which took place following Smash Comics # 32.
Jester--The Jester was a Quality character who migrated from Earth-2 to Earth-X in 1942 in All-Star Squadron # 50, which occurs between Smash Comics # 36 and 37.
Jimmy Olsen--See Superman.
Johnny Peril--This is set on Earth-2 mainly because the series began during the golden age. But there are no crossovers to truly validate his inclusion on Earth-2. His final Earth-2 appearance was Unexpected # 213, August 1981.
Johnny Quick--This speedster was a core member of the All-Star Squadron. His final Earth-2 appearance was Secret Origins # 7.
Johnny Thunder--This hero was a member of the JSA and All-Star Squadron. His final Earth-2 appearance was All-Star Squadron # 60. His first post-crisis appearance was All-Star Squadron # 67, March 1987.
Joker--See Batman.
Justice League of America--This team is considered to be the Earth-1 counterpart of the Justice Society of America, though it's roster and adventures are different.
Justice Society of America--This team is the core that ties together Earth-2, and in fact, this series was the start as it showed that in it's first appearance eleven different series (Superman, Batman, Flash, Green Lantern, Hawkman, Atom, Spectre, Doctor Fate, Sandman, Hourman, and Scribbly) all co-existed within the same shared reality. The JSA operated from 1940 to 1951, and then returned and operated from 1962 to 1985. The team's final Earth-2 appearance (operating as a team) was in All-Star Squadron # 60. Following that, the team that was portrayed was the post-crisis version. The team's first post-crisis appearance was All-Star Squadron # 67, March 1987.
Kid Eternity--Was from Earth-S, operating in the golden age.
King--The King is assumed to be in Earth-2 simply because of his operating in the golden age, but there is no crossover connection to substantiate that. His final Earth-2 appearance was All-Flash # 13, Winter 1943.
Liberty Belle--Liberty Belle was another core member of the All-Star Squadron. Her final Earth-2 appearance was Secret Origins # 7.
Little Boy Blue--Little Boy Blue is another character placed on Earth-2 simply because he operated in the 1940s. He has no connection to other Earth-2 characters. His last Earth-2 appearance was Sensation Comics # 82, October 1948.
Lois Lane--See Superman.
Manhunter (DC)--This character operated on Earth-2 in the 1940s, then was part of the great migration of the early 1950s where several Earth-2 heroes moved to Earth-1 under mysterious circumstances in an untold story. On Earth-1 he was cloned by some secret society, and he found himself having to fight his clones. This pre-crisis character's last pre-crisis appearance was All-Star Squadron # 60. Note that his inclusion in the All-Star Squadron establishes him on Earth-2, but his meeting the Silver Age Batman in the 1970s confirms his migration.
Manhunter (Quality)--This character started on Earth-2 (operating at the same time as the other Manhunter) and like his namesake, left Earth-2, but this time for Earth-X. This happened in All-Star Squadron # 50, which occurs between Police Comics # 12 and 13.
Martian Manhunter--Though this character is from Earth-1, he may have an Earth-2 counterpart. Roh Kar, Manhunter from Mars, is a red Martian who appeared in Batman # 78, September 1953.
Marvel Family--Operated in the 1940s on Earth-S, but they did visit Earth-2 in 1942.
Mary Marvel--Operated in the 1940s on Earth-S, but they did visit Earth-2 in 1942.
Merry, Girl of 1,000 Gimmicks--Merry was a spin-off of the Star Spangled Kid. Her final Earth-2 appearance was Star Spangled Comics # 90, March 1949.
Midnight--Another Quality character who migrated from Earth-2 to Earth-X in All-Star Squadron # 50, occurring between Smash Comics # 36 and 37.
Minute Man--Operated in the 1940s on Earth-S.
Miss America--This Quality character died in All-Star Squdron # 31 - 32, which occurs after Military Comics # 7.
Mister America--aka Tex Thompson and the Americommando. Was a member of the All-Star Squadron. His final Earth-2 appearance was All-Star Squadron # 60.
Mister Terrific--A member of the JSA. He was actually murdered on the Justice League's Earth-1 satellite headquarters. His final Earth-2 appearance was All-Star Squadron # 60.
Newsboy Legion--Part of Earth-2 established from a crossover with the Sandman and the Boy Commandos and confirmed in All-Star Squadron. They later migrated to Earth-1 in the Great Migration. They grew up to run Project Cadmus and were each cloned, creating a new Newsboy Legion. On Earth-1, they were a major part of the storyline of Superman's Pal Jimmy Olsen, establishing that they were indeed now on Earth-1. Their final pre-crisis appearance was All-Star Squadron # 44.
Nightwing--See Batman.
Phantom Lady--This one is complicated. There are actually two alternate versions of this character. On Earth-2, Phantom Lady was the cousin of Starman. She was a member of the All-Star Squadron, and then migrated to Earth-X with the Freedom Fighters in All-Star Squadron # 50, which took place between Police Comics # 11 and 12. Her final golden age appearance was Police Comics # 23, October 1943. When she reappeared in Justice League of America # 107, September 1973, it was revealed that the Nazis had won World War II on Earth-X. This Phantom Lady's last pre-crisis appearance was Crisis on Infinite Earths # 11. Now there was also a Phantom Lady on Earth-4. Her Quality stories also occurred on Earth-4 during the 1940s, but she was not part of any hero team nor related to Starman. She didn't migrate to another Earth, and the Allies ended up winning WWII. Instead, following Police Comics # 23, her stories continued in stories published by Fox and Ajax-Farrell, that went into the 1950s, where she then must have retired, as no further stories have been published of this version since then.
Plastic Man--Plastic Man began on Earth-2, where he was a core member of the All-Star Squadron, but then in 1942, he migrated to Earth-X with the Freedom Fighters. This occurred in All-Star Squadron # 50, which takes place between Police Comics # 12 and 13. Plastic Man later migrated to Earth-1, though the other Freedom Fighters assumed he died. His migration must have occurred between Plastic Man # 52, February 1955, and Plastic Man # 7, November 1967. Interestingly, his son carried on as Plastic Man on Earth-1, but there already was an Earth-1 counterpart of the original Plastic Man who was operating at the same time.
Power Girl--Power Girl is an anomaly in many ways. First, usually when there were instances where the same character existed on both Earth-1 and Earth-2, the Earth-2 character came first. (Usually it was a 1940s Earth-2 character being recreated as a 1960s Earth-1 character.) But Power Girl is a 1970s character that was the Earth-2 counterpart of Earth-1's Supergirl from the 1950s. Power Girl was Superman's cousin. She was actually older, but her rocket took longer to reach Earth, and she was kept in suspended animation, so she was still a teen when she arrived, while her cousin was now old. She joined the JSA's Super Squad. Anomaly number 2: Following the Crisis, Earth-2 seemed to cease to exist. But Infinite Crisis revealed that although Earth Post-Crisis was a different reality, the post-crisis JSA had suppressed memories of Earth-2. This wasn't adequately explained, but when Alex Luthor recreated the multiverse, the JSA were drawn back to Earth-2. (This Earth-2 didn't last.) Following Infinite Crisis, on New Earth, the JSA of that Earth now could remember Earth-2, even though they also remembered the new history. So since this wasn't adequately explained, I have to theorize. I believe that when the previous universes merged, then vanished, the characters souls became imprinted upon their post-crisis counterparts. So before the crisis, they were separate beings, but after, they were merged, but since Earth Post Crisis was the existing reality, the Earth-2 memories were suppressed. Only when Superman of Earth-2 arrived on Earth-Post Crisis did those memories surface. When Earth-Post Crisis was replaced by New Earth, the previous incarnations from both worlds merged with the New Earth characters, but the after effect of three souls merging was that the Earth-2 beings were copied and placed on a New Earth-2. So back to Power Girl. When this merging happened, Power Girl and Supergirl both tried to imprint themselves onto Kara Zor-El of Earth-Post Crisis. However, only this had an odd effect, in which multiple versions emerged. One of Linda Danvers, an ordinary girl who would later be killed by a demon. Another was Laurel Gand in the 30th century. Another was Kara, a Kryptonian survivor (until killed by Aliens.) And another was Kara Zor-El (who at the time was still in a rocket headed to Earth). Earth-1's Kara Zor-El herself found herself unable to imprint herself and remained a ghost on this new world. Power Girl though was transported to Earth Post Crisis physically, but her memories got scrambled. Power Girl felt "feedback" whenever she encountered one of her counterparts, and eventually had her memories restored when she met her cousin again. On New Earth, she once again was the same person. She thought that perhaps New Earth-2 was her Earth-2, but soon discovered that that world had it's own Power Girl (a cosmic copy of her.)
Quicksilver--This is a Quality character who presumable migrated from Earth-2 to Earth-X at some point though the story was never told. Likely it was shortly after All-Star Squadron # 50, perhaps between National Comics # 21 and 22. His final pre-crisis appearance was National Comics # 73, August 1949.
Ray--The Ray was a member of the Freedom Fighters who made the migration from Earth-2 to Earth-X in All-Star Squadron # 50, which occurs between Smash Comics # 36 and 37. His final pre-crisis appearance was Crisis on Infinite Earths # 12.
Red Bee--The Red Bee died on the first mission of the Freedom Fighters in All-Star Squadron # 31 - 35, which takes place following Hit Comics # 24.
Red Tornado--There were actually two heroes called the Red Tornado on Earth-2. The first was Ma Hunkel, who fought crime in the 1940s. The second was a robot created by T.O. Morrow to destroy the Justice Society of America, but he instead turns good and migrates to Earth-1 to join the Justice League of America.
Robotman--Robotman was a core member of the All-Star Squadron, who was part of the Great Migration to Earth-1, as revealed in a flashback in Justice League of America. His final pre-crisis appearance was Secret Origins # 7.
Rose and the Thorn--See Green Lantern and Flash.
Roy Raymond, TV Detective--Though his career started in 1949, this character existed on Earth-1. His only crossovers were with the Silver Age Superman and the Justice League of America.
Sandman--The Sandman was a member of the JSA and All-Star Squadron. His final Earth-2 appearance was Secret Origins # 7. On Earth-1, the Sandman is a man who can actually enter dreams.
Sargon the Sorcerer--Was a member of the All-Star Squadron, and part of the Great Migration as revealed in Justice League of America. His last pre-crisis appearance was All-Star Squadron # 60.
Secret Society of Super-Villains--Though mostly operating on Earth-1, this team had members from Earths-1, 2, and 3.
Sergeant Rock--This one is tricky. Note first that Sgt. Rock links to all the other war comics characters through various team-ups. So this actually applies to all DC war comics. Sgt. Rock seems to be from Earth-1, since he has teamed with the silver age Batman, and also a time lost Earth-1 Superman. But...he also teamed with the golden age Batman, and also during Crisis on Infinite Earths, when he encounters heroes from the future, he assumes they are members of the All-Star Squadron who operate stateside.
Seven Soldiers of Victory--This team consisted of the Crimson Avenger, the Star Spangled Kid, Stripesy, Green Arrow, Speedy, the Shining Knight, and the Vigilante. In 1948 a villain sent them all to different time periods where they were trapped. Some of these members had published adventures after 1948, but they must all have occurred before 1948. They were rescued in the 1970s by the JLA and JSA and then disbanded. Their final Earth-2 appearance as a team was All-Star Squadron # 60.
Shining Knight--An Earth-2 characters whose adventures began in 6th century Camelot, but after an enchantment froze him in ice and placed him in suspended animation, he was revived just in time for World War II. He was a core member of the All-Star Squadron, but served mostly in England. As a Soldier, he was sent back in time and stranded in 1948. However, he had published adventures up to 1951, which must occur prior to 1948. He was rescued and returned to the present in the 1970s, but then went back to live in the 6th century. His final Earth-2 appearance was All-Star Squadron # 60.
Slam Bradley--Though a 1940s detective, his only connection is to the Silver Age Batman, thus placing him on Earth-1.
Spectre--Jim Corrigan died but God resurrected him giving him the power to have his ghost come out of his body and operate on it's own. The Spectre served with the JSA and All-Star Squadron. In 1951, after the JSA disbanded, the Spectre being left Jim Corrigan, and traveled to Earth-1, arriving in 1966, where he possessed Jim Corrigan's Earth-1 counterpart. The Spectre's final pre-crisis appearance was All-Star Squadron #60, which was also the Earth-2 Corrigan's final appearance. The Earth-1 Corrigan's final appearance was Last Days of the Justice Society Special # 1, 1986. His first post-crisis appearance was All-Star Squadron # 67, March 1987.
Spy Smasher--Operated on Earth-S, but post crisis was a member of the All-Star Squadron.
Star-Spangled Kid--The Star-Spangled Kid was a member of the Seven Soldiers of Victory. In 1948 he was trapped in the past, and rescued in the 1970s. His final Earth-2 appearance was New Teen Titans # 31, May 1987.
Starman--Starman was a member of the JSA and All-Star Squadron, and cousin of Quality's Phantom Lady. His final Earth-2 appearance was Secret Origins # 7. On Earth-1, Starman is an alien who rules an empire.
Steel, the Indestructible Man--Steel was a character that was created for a series (short lived) in the 1970s, but based in the 1930s, and was either a homage or rip-off of Captain America. In All-Star Squadron, Steel was shown to be part of Earth-2. During the Crisis, Steel was shown to be sucked through a portal and thrown to Earth-1. In Justice League of America, he was now an old man and his grandson had joined the JLA. Steel's last pre-crisis appearance was Justice League of America # 246, January 1986. Appearances after that were his Post Crisis counterpart.
Streak the Wonder Dog--Was a spin-off of Green Lantern. His last Earth-2 appearance was Sensation Comics # 93, September 1949.
Superman--Superman is considered the first super-hero (or mystery man) of Earth-2, even though Doctor Occult could be argued to the first. Superman was a member of the JSA and All-Star Squadron. During the Crisis on Infinite Earths, Superman and Lois Lane, along with Superboy of Earth-Prime and Alex Luthor of Earth-3, became trapped in a limbo reality until Superman escaped to Earth Post Crisis. This sparked the Earth-Post Crisis counterparts of Earth-2 heroes to start remembering Earth-2. Lois Lane and Superman both died during this Infinite Crisis. On New Earth, this Superman was revived as a member of the Black Lantern Corps briefly.
See the dividing line between the Earth-1 and Earth-2 Superman (part 1) and (
part 2). Note that when Superman was a teen, he was visited by Superboy of Earth-1, who helped train his Earth-2 counterpart.
Tarantula--Was a core member of the All-Star Squadron. Final Earth-2 appearance was Secret Origins # 7.
Tomahawk--This hero of the American Revolution was firmly established as being Earth-2 in All-Star Squadron, and his stories were indeed published beginning in the 1940s.
TNT and Dan the Dyna-Mite--Golden age heroes. Final Earth-2 appearance was All-Star Squadron # 60.
Uncle Sam--Uncle Sam (from Quality) was a member of the Freedom Fighters who migrated from Earth-2 to Earth-X. The migration was in All-Star Squadron # 50, which took place between National Comics # 25 and 26. His final pre-crisis appearance was Crisis on Infinite Earths # 12. His first post crisis appearance was Secret Origins # 19, October 1987.
Unknown Soldier--There is evidence to support the Unknown Soldier's existence on both Earths-1 and 2. Superman of Earth-1 met this character, but so has the golden age Batman.
Vigilante--The Vigilante was a member of the Seven Soldiers. His adventures of the golden age continue to 1954 in print, but have to all occur before 1948 since he was sent and trapped in the past at that time. After he was rescued in the 1970s, he returned briefly to adventuring. His final Earth-2 appearance was All-Star Squadron # 60. The Vigilante has an Earth-1 counterpart.
Whip--A golden age hero, whose final Earth-2 appearance was All-Star Squadron # 60.
Wildcat--A member of the JSA. His final Earth-2 appearance was All-Star Squadron # 60.
Winky, Blinky, & Noddy--A spin off of the Flash, whose final Earth-2 appearance was All-Flash # 29, June 1947.
Wonder Woman--Member of the Justice Society of America. During the Crisis, the Earth-1 Wonder Woman was reborn as the post crisis Wonder Woman. Meanwhile, the Earth-2 Wonder Woman was invited to move to Mount Olympus (which exists in all realities at the same time.) She returned during Infinite Crisis to guide the Post Crisis Wonder Woman.
See the dividing line.
Young All-Stars--This team operated in the golden age only in post-crisis stories. They were not part of Earth-2 continuity.
Zatara--Part of the Great Migration, he moved to Earth-1 and met Superboy, before having to banish himself to other magical realms. Finally, his daughter Zatanna broke the spell and he was able to come home. His final Earth-2 appearance was All-Star Squadron # 60.
So, to sum up. In Crisis on Infinite Earths # 10, several heroes from various alternate Earths altered time, effectively eliminating the multiverse and replaced it with one merged Earth. On this Earth, elements from Earths 1, 2, 4, S, and X combined into one reality. Where there were conflicts, the Earth-1 elements overtook the rest. All the heroes that had traveled to the dawn of time to change history remembered the old realities, and the ones who had been in the past during the merging who ceased to exist actually ended up still surviving. Thus most people on Earth-2 (the billions of normal people) ceased to exist since there was already Earth-1 counterparts. But the Earth-2 heroes and villains that had been exclusive to Earth-2 now existed on Merged Earth, with some remembering the old times. The anomaly heroes survived, though only those with old memories remembered them. This universe wasn't meant to be however. In actuality, two cosmic beings, Mechanique in the 1942 of Earth-2 and Aphrodite in 1985 of Earth-2, had been holding back the full effects of the Crisis for their own purposes, but when their goals were met, they released their hold, and Merged Earth ceased to exist, replaced by Earth-Post Crisis, a universe still combining those previous five Earths, but this time history was drastically altered in the lives of some heroes. Also, all pre-crisis memories were forgotten by almost everyone. (There were a few exceptions.) As for Earth-2 characters, they were gone (but see my entry for Power Girl). But their spirits survived and were imprinted upon their Earth-Post Crisis characters, which is why during Infinite Crisis, memories of Earth-2 surfaced. Following Infinite Crisis, Earth-Post Crisis ceased to exist, and was replaced by a multiverse of 52 Earths, all the same, until Mr. Mind recreated them all to be different. The characters originally from Earth-2 were moved to New Earth with another new reality history, but the same souls now merged with three different versions. This caused a cosmic backlash in which those characters were echoed on the alternate New Earth-2.
So...Flashpoint. Apparently following Flashpoint, the characters originally from Earth-2 no longer exist on New Earth, and only on Earth-2.
