As the Inferior Five series (which was, I believe, originally intended to take place on Earth-1) involved many of the standard Silver Age DC characters in cameos, I have used some Earth-1 stories to provide background information for the timeline.
(thanks to Ronald Byrd, Time Trust, John McDonagh for Baitman info, John Censullo for series summaries and Crazy Ivan for Books of Magic info)
59,600 B.C.
Superman and Aquaman travel to Atlantis, according to their approximation, fifty thousand years before it is destined to sink. [Super Friends #18]
48,000 B.C.
The continent of Atlantis sinks, leaving only a few island remains of its once great cultures, including Cerdia, Poseidonis, Therna Na Oge, and Tritonis. A surviving colony takes the name of Oompah. [Inferior 5 #3]
c. 30 B.C.
Prince Algon of the city of Ma-Phoor (somewhere south of Ethiopia) becomes the first Metamorph. He is the betrothed of Queen Jezeba (a dead ringer for Sapphire Stagg). [Metamorpho #16-17]
1649
October
Wonder Woman and Robin travel to Madrigal, Spain, where they aid Princess Isabella of Castile. [Super Friends #18]
1790's
Sir Chauncey Berkeley, also known as the Crimson Chrysanthemum, helps aristocrats escape from France during the Reign of Terror. The Inferior Five time-travel from November 1967 to the French Revolution where they help the Crimson Chrysanthemum save Charles Darnit, rightful Marquis St. EvrŽman, from Madame Defarce. [Inferior 5 #5]
1860
Batman travels to Michigan in 1860, where he meets a young Tom Edison. [Super Friends #18]
1920's
Reed Victor becomes the masked lawman known as Yellowjacket, adventuring with his chauffeur-aide Plato who drives the automobile named the Gold Bug. [Inferior 5 #1]
1925
Famed Chinese detective Charlie Chum has first public case. He later teaches the daughter of his best friend Prof. Theo O'Day all he knows about detective work. [ref. Angel & the Ape v2#2]
1929
Allergy Queen has first public case as detective. [Inferior 5 #7]
1936
The archeologist Maryland Smith has adventures. [Adventures of the Rifle Brigade #1-3]
1938
Mr. Brent, strong enough to shatter concrete or turn boulders into sand with his bare hands, becomes Mr. Might. He was born Barb-Ell of the planet Neon, son of Dumb-Ell. After the citizens of Neon ignored his warnings of their planet's pending destruction, Dumb-Ell sent his son Barb-Ell in a rocket to Earth. However, Dumb-Ell really was a crackpot, and Neon never did explode. [Inferior 5 #1]
1939
John Claypool, Lord Gravestone has first public case as Darwin of the Apes. He eventually marries and settles down with his wife, Jayne. [Inferior 5 #3]
Prince Nabob has first public case as the Sub-Moron/Sunk Mariner. [Inferior 5 #7]
1940
Jason Cramer, who can run and fly at fantastic speeds, becomes Captain Swift.
Ellen Pasken comes from an unknown land under the sea to become the Mermaid.
Victor Victor, the son of Yellowjacket who gathers his great stamina from the people who still believe in the American dream, becomes the Patriot.
Lady Berkeley, a descendant of the Crimson Chrysanthemum and an expert in judo and karate who also carries the "Torch of Freedom" which serves her as an offensive weapon and the "Book of Justice" as her defensive weapon, becomes Lady Liberty.
Joseph Jones becomes General Glory.
1941
Artemis (?) emigrates to America from a race of Amazons to court Steve Tremor and become Power Princess. [The Amazons are revealed to be subterranean in the Angel & the Ape mini- series. This may be a reference to the 19th century novel "The Coming Race" by Edward Bulwer "dark and stormy night" Lytton. The novel is the story of the protagonist's exploration of a matriarchal subterranean civilization. The people of this world are call the "Vrilya", and have power over a force call the "Vril"]
Mortimer King becomes the Bowman.
Theodore Knight becomes Starman I. [Adventure #61]
Eels O'Brien becomes Plastic Man. [Police #1, ref. Inferior 5 #2]
In Germany, the Masked Swastika has first public case.
1942
Thomas N. Thomas & Daniel Dunbar become TNT & Dan the Dyna-Mite. [Star-Spangled #7, ref. Super Friends #12, Superman Family #190]
Theodore Grant becomes Wildcat. [Sensation #1]
1941-1945
The Bowman, Captain Swift, Lady Liberty, Mr. Might, the Mermaid, the Patriot, and Power
Princess gather together as The Freedom Brigade.
1944
The British Commando Unit Captain Darcy and his Rifle Brigade travel to the Middle Eastern country of Sidi Boomboom, where they compete with the American adventurer known as Maryland Smith in "Operation Bollock." [Adventures of the Rifle Brigade #1-3]
1945 - 1946
Clark Kent/Kal-El, one of the last survivors of the exploded planet Krypton, begins his career as Superboy.
Freedom Brigade disbands.
late 1940's - early 1950's
Tur-Tel, the last survivor of the planet Galapagon, begins his career as Super Turtle. [Adventure #304/Silver Age 80-Page Giant #1] [Henry Boltinoff]
On an alternate possible Earth, Prof. Theo O'Day marries Princess Power, believing he can handle living with a woman with super-powers, but he discovers that he can't and leaves her after his daughter, Athena, is born. Prof. O'Day supports his daughter, but needs a more normal relationship. He marries another woman, but she dies soon after giving birth to his second daughter, Angel. Princess Power returns and takes the two of them in. The couple soon re-marries.
1950
Bob Hope begins over a decade of adventures. [Adventures of Bob Hope]
1951
Terrance Thirteen becomes Dr. 13, the Multiple Man. [cf. Doom Patrol #53]
1952
The Phantom Stranger has first public case. [cf. Doom Patrol #53]
Dean Martin and Jerry Lewis begin over five years of adventures together (they are not Hollywood stars in their comic book, but Jerry Lewis is clearly depicted as such on Earth-1 in Jimmy Olsen #64). [Adventures of Dean Martin and Jerry Lewis #1]
On an alternate possible Earth, Prof. Theodore O'Day and his daughter Angel discover and adopt Sam, an intelligent gorilla. [Showcase #77]
1954
Clark Kent/Kal-El begins his career as Superman. [ref. Showcase #63]
Bruce Wayne begins his career as Batman. He is soon accompanied by Dick Grayson as Robin, the Boy Wonder. [ref. Showcase #62]
1956
Barry Allen becomes the Flash in Central City. [Showcase #4, ref. Showcase #62]
Bart Hawk, an American living in Poland, survives a Russian bombing raid which kills his family; he gathers together allies from a variety of NATO countries to battle communists under the name Blackhawk. [Blackhawk #108 (extrapolation based on first DC issue); ref. Inferior 5 #2]
Ace Morgan, Prof Haley, Red Ryan and Rocky Davis, narrowly escaping a plane crash, decide to make the most of their borrowed time as the Challengers of the Unknown. [Showcase #6, ref. Inferior 5 #2]
1957
Dean Martin, perhaps fearing for his safety and/or sanity, ceases to accompany Jerry Lewis on his adventures. [Adventures of Jerry Lewis #41]
1958
Oliver Queen & Roy Harper become Green Arrow & Speedy in Star City. [Adventure #250, ref. Showcase #62]
1959
Abin Sur crash-lands on Earth and in his dying moments enlists test pilot Hal Jordan into the Green Lantern Corps in Coast City. [Showcase #22] Shortly before this, on a previous visit to Earth, he had enlisted unemployed student Jeremy Baxter into the Green Lantern Reserves. ["The Few, The Proud"]
1960
Mr. E, the Malleable Mystic, has first public case. [cf. Doom Patrol #53]
Dane Dorrance, John Payton, Biff Bailey, and Judy Walton meet when, individually, they all go searching for the same sunken treasure, and remain together as the Sea Devils. [ref. Inferior 5 #2]
Superman, Batman, Flash and other heroes form the Justice League of America. [ref. Showcase #63] [see Appendix I]
1961
Ray Palmer becomes the Atom in Ivy Town. [Showcase #34, ref. Inferior 5 #2]
1962
Cobweb Kid has first public case. [Inferior 5 #7]
Dr. Will Magnus creates Iron, Lead, Gold, Mercury, Platinum, and Tin who band together as the Metal Men. [Showcase #37, ref. Showcase #65]
1963
Iron Pants has first public case. [Inferior 5 #7]
Niles Caulder (the Chief), Cliff Steele (Automaton), Larry Trainor (Negative Man) and Kay Challis (Elastiwoman) form the Doom Patrol/Legion of the Strange [My Greatest Adventure #80, ref. Showcase #63, cf. Doom Patrol #53]
1964
Jerry Lewis dons spring-equipped shoes and briefly assumes the costumed identity of the Tarantula. [Arnold Drake & Bob Oskner] [Adventures of Jerry Lewis #84]
Robin and other heroes form the Teen Titans. [Brave & Bold #54, ref. Showcase #63] [see Appendix I]
1965
Rex Mason becomes Metamorpho. [Brave & Bold #57, ref. Showcase #65]
mid- to late-1960's
Dr. 13, Phantom Stranger, Mr. E, and John Constantine (Hellblazer) form the Mighty Mystics, operating from their orbital headquarters the Hand of Warning. [cf. Doom Patrol #53]
1966
The son of Eels O'Brien becomes Plastic Man II. [ref. Inferior 5 #2]
Stanley & his Monster have first adventure. [Fox & Crow #95, ref. Inferior 5 #7] [Arnold Drake & Winslow Mortimer]
Myron Victor (Merryman, the son of Patriot & Lady Liberty), Athena Tremor (Dumb Bunny, daughter of Princess Power and Steve Tremor), Leander Brent (Awkwardman, son of Mr. Might & Mermaid), Herman Cramer (Blimp, son of Captain Speed) and William King (White Feather, son of the Bowman) become the Inferior 5. [Showcase #62] [E. Nelson Bridwell & Joe Orlando]
"Brute" Brainard briefly becomes the Man-Mountain. [Showcase #63]
Dean Egghead's Academy for Superheroes sponsors the Egg's-Men, teen-age evolutionary throwbacks, consisting of Harry McElhinney (the Ape), Irish Autumns (Basilisk), Melvin Murgatroyd XIV (Icarus), Billy Gander (Winter Wonderlad), and Penelope Pink (Levitation Lass). They are later joined by Calvin Rankin (Mimic).
The popularity of a documentary television series which recounts some of Batman & Robin's greatest cases leads to a rash of imitators, including Catman & Kitten, Fatman & Tubbin, Flatman and Ribbon (the Taped Crusaders), Ratman and Rotten the Boy Blunder, Sadman and Sobbin' (the Crying Crimefighters), and so on and so on. [The Adventures of Jerry Lewis #97]
[speculated] Billy Baxton becomes Captain Marvel. [Power of Shazam #27]
1967
The Inferior Five hook up with Caesar Single and Kwitcha Belliakin of Competent Organization Utilizing Scientific Investigation for National Fiend, Ruffian, and Evildoer Defense (C.O.U.S.I.N.F.R.E.D.) to thwart the plans a group of Heinous, Unscrupulous Rats and Rogues Initiating Criminal Anarchy and Nefarious Evil (H.U.R.R.I.C.A.N.E. Agents). H.U.R.R.I.C.A.N.E.'s main agents are Powerhouse, the Missing Fink, Mr. Mental, the Yellow Streak, Blackbird, "Tabby" Katz, "Nitro" Gleason, and "Crabgrass" Wilde. [Inferior 5 #1]
Rod Rickard (Mr. Manplastic), Jerry Drizzle (the Matchstick Kid), Sophie Rickard (Vanishing Queen), and Bjorn Andersen (Whatchamaycallit) form the Kookie Quartet. [Inferior 5 #2]
Hector Prynne (King-Size) and Janice Prynne (The Terrible Tse-Tse Fly) begin their criminal careers. [Inferior 5 #2]
Thor, red-bearded god of thunder hailing from Asgard, comes to Earth as crimefighter, taking the secret identity Don R. Blitz. [Inferior 5 #4]
1968
The Fox & The Crow travel from Earth-C. [Inferior 5 #7]
Merryman, Dumb Bunny, Awkwardman, the Blimp, White Feather attempt to rename themselves The Fearless Five (with limited success). [Inferior 5 #9]
On an alternate possible Earth, Angel & the Ape (Angel O'Day and Sam Simeon) have first public case as detective agency. [Showcase #77]
1972
Prez Rickard becomes the first 18-year-old to win a Congressional election; an amendment to the Constitution is voted in which lowers the required age of the President from 35 to 18. [Prez #1]
1976
Senator Prez Rickard, running on the new Flower Party ticket, is elected President. During his term he assigns Eagle Free to be the new F.B.I. Chief, renames Air Force One "The Free Bee", and encounters Supergirl (Linda Lee Danvers/Kara Zor-El). [Prez #1-4, Supergirl V3#10]
1977
Joshua Clay joins the Doom Patrol/Legion of the Strange as Tempest [note: date from Showcase #94; actual Earth-12 affiliation may not occur until later]
On an alternate Earth-12, the universe is destroyed by a visiting Mr. Mxyzptlk and Bat-Mite of Earth-1. [World's Funnest]
1978
Earth-1 is dragged out of its orbit and is transported through space at faster-than- light speed, causing weird temporal side-effects. The heroes of Earth meet to figure out a way to stop the menace. The Justice League head off into space, while the Teen Titans, Metal Men, and others tend to Earth. A number of reality-displaced heroes, including the Inferior Five, congregate at the office of Angel O'Day and Sam Simeon. The heroes finally defeat the alien menace, Earth-1 is returned safely to it's proper orbit around the Sun, and the reality-displaced heroes are returned to their home. [Showcase #100]
1983
Dorothy Spinner joins the Doom Patrol/Legion of the Strange as Spinner.
1986
Sigfried Horatio Hunch III becomes 'mazing man. ['mazing man #1] [Bob Rozakis & Stephen DeStefano]
The Inferior 5 briefly visit Earth C and encounter Captain Carrot and the Zoo Crew. They may still be attempting to return home from the events of 1978. [Oz-Wonderland Wars #3]
1988
Baitman has adventures. [When DC published the November 4, 1988 edition of The Daily Planet, page 13 showed various parodic DCU comic strips, including Captain Carrot and Baitman. The Baitman strip by Bill Hinds has in an alley behind Generic National Bank, the Embezzler making his get away. Baitman shows up-just some guy in fisherman clothing with a cape, confronts the Embezzler, tells him that he switched the bag so that is filled with leeches not money (Embezzler was holding a bag with what he thought was money in it).]
1989
Roxanne "Roxy" Davis (daughter of Rocky Davis), Paul Haley (son of Prof Haley), and the son of Ace Morgan & June Robbins battle the Phantom of the Fair. [Challengers of The Unknown #39]
early 1990's
The Head (formerly Nile Caulder, the Chief), organises Crying Boy (Kenneth Most), the Australian heroine known as Flux (Danii Melvin), the Scratch (Morgan Morgan), Spinner (Dorothy Spinner) and Shasta the Living Mountain into the Doom Force. [Doom Force #1]
1994
Jack Knight takes on the mantle of Starman. [Starman v2 #0]
1995
The alien known as Mikaal Tomas is rescued from circus owner Bliss's sideshow by Jack Knight and subsequently accompanies him as Mikky the Nova Boy.
late 1990's
Plastic Man Red & Plastic Man Blue battle the Hall-Monitor in the Onslaught of the Secret Genesis Wars Agenda. [Plastic Man Special #1]
2152
A time-traveling Jack Knight & Mikky visit here and rescue post-Glasnost Russian hero Leonid Kovar (Starfire) of their own era, from space tyrant Jarko the Jovian; they also encounter Tommy Tomorrow & the Planeteers.
30th century
start the Legion of Superheroes [ref. Inferior 5 #2]
NOTES:
Wonderfella is a comic character created by Myron Victor (Merryman). I hesitate to even speculate about an Earth one level further removed from reality than Earth 12, though it may also be the home of the multitalented adventurer Colenol Porterhouse who appeared in Whiz Comics. At BZ Comics, 'mazing man's associate and Earth-C emigrant Denton Fixx worked on Zoot Sputnik (who appears in All-Fun Comics), Wonderful Woman, Splendidman, and others. At DZ Comics, Sam Simeon created successful characters like Attilla Gorilla and The Deus Ex Machina Man. There is also a newspaper strip, created by a cartoonist named Wendell and much beloved of Jerry Lewis, entitled Flame Farrell.
Dennis Powers observes that a collection of Victor family portraits also revealed a masked cowboy, a masked cabellero with a sword and a whip, a man on horseback who was either a Bedouin or a Cossack and another man in an urban setting leaping or flying from the top of a building (he wore a skintight suit with cape, boots and a cowl with long ears or antenna).
APPENDIX I: The Justice League
There is canonical support for the existence of Superman on Earth-12, as well as the presence of a Justice League. What we have seen of Superman-12 suggests he is very msimilar to the Silver Age Superman, though his adventures appear to be more amusing and mcartoony. I therefore propose that the (comic book version) of The Super Friends takes mplace on Earth-12; this has a sense of appropriateness and would supply a lineup for the mJLA. However, I have opted not to include the SF series formally within the timeline, mbecause it would bias it excessively towards events which parallel Earth-1, thus distracting from its uniqueness. If the SF series is taken as canonical, other heroes active on Earth-12 include Aquaman, Aqualad, Batgirl, Black Canary, Black Orchid, Bushmaster, Dr. Mist, Elongated Man, the Freedom Fighters, Godiva, Green Fury, Hawkman, Hawkgirl, Icemaiden, Impala, Jack O'Lantern, Krypto, Little Mermaid, Lori Lemaris, Mera, Nubia, Olympian, Owlwoman, Rising Sun, Seraph, Tasmanian Devil, Thunderlord, Tuatara, Wild Huntsman, and Wonder Woman. It did appear that some of the events which occured in the SF series had ramification on Earth-1, but it is not unusual for events on one Earth to be reflected with some variants on another. I think it best to remain non- commital regarding the origins of the Earth-12 Black Canary and Freedom Fighters.