The Elongated Man and the Bronze Age Timeline!

Around 1973, there were some major changes in the tone and tendencies of comics:

• We see some mature topics: sex, drugs, racial issues, politics.
• There's an increased interest in diversity of genre.
• "Super science" ceases to be the mayor source of super powers.
• A lot of themes come from movies: Swamp Thing and Manbat are examples of horror, Rupert Thorne and Tobias Whale draw inspiration from The Godfather, Ra's Al Ghul from the James Bond franchise, Hex from western, etc.
• We see more returning characters and plots than new ones.
• New characters tend to be minorities.
• The Multiverse is widely explored, more stories and titles take place outside Earth-1.
• The Golden Age characters are widely revived.

This era is called the 'Bronze Age of Comics'. Some authors consider it an era on it's own and some consider it part of the Silver Age. Some common characteristics are that, contrary to the 'Modern Age of Comics' (c. 1986 - present), both:

• Are set in a multiverse,
• Share the same continuity,
• Feature mainly a different story every issue,
• Feature simple, over-explained writing,
• Avoid killing off characters, and
• Avoid tabú topics like sexual abuse or homosexuality.

At the end of the classic period of the Silver Age, the Elongated Man lost his ongoing Detective Comics feature, so, during the rest of it and the Bronze Age, he became a permanent member of the Justice League of America and got sporadic back up stories in Detective Comics, Flash, DC Presents, and once in the Justice League of America itself.

As a member of the Justice League, he replaced the Martian Manhunter, another super powered detective (oddly enough, he can stretch just as well and also lost his 'tec feature to Elongated Man back in '64), whose popularity faded drastically since the late 60s. The team starts expanding its roster to 16 members by 1980. Now it features the main silver age heroes, a couple of minor ones (Zatanna and Red Tornado) and, Firestorm, a completely new one at the time.
This era ends as the industry start imitating the sophisticated style of Chris Claremont, John Byrne, Frank Miller and Alan Moore, who take influences from postmodernism and place these fantastic characters in contrastingly realistic situations. 

1973

January: Anton Arcane, Patchwork Man, Cranius, Orphidian (Swamp Thing #2).

February:

• Captain Marvel and his supporting cast debuts on DC as part of Earth-S (Shazam! #1).

March: Abigail Arcane (Swamp Thing #3).

April:

• Elongated Man joins the JLA (Justice League of America #105),
• the Spook (Detective Comics  #434).

July:

• Black Orchid (Adventure Comics #428),
• Red Tornado joins the JLA (Justice League of America #106).

October: E-man (E-man #1, Charlton Comics).

1974

February:

• The Spectre and Jim Corrigan of Earth-1 (Adventure Comics #431),
• Toyman II (Action Comics #432).

March: The Werewolf (Batman #255).

May: Injustice Gang (Justice League of America #111).

June: Lt. Harvey Bullock (Detective Comics #441).

October:

• OMAC (OMAC #1),
• Inspector Henderson from classic radio (c. 1940) and 50s TV show is introduced to the Earth-One continuity (Action Comics #440).

November: Vartox (Superman #281).

Winter:

Sandman, Brute & Glob (Sandman #1).

1975

April: Sterling Silversmith (Detective Comics #446).

November:

• Warlord, Skartaris, Tara, Deimos (First Issue Special #8).

1976

January: Powergirl (All-Star Comics #58).
February: Kobra (Kobra #1).
April: Blackrock (Action Comic #458).
May:

• Secret Society of Super Villains (Secret Society of Super Villains #1).

June: Captain Stingaree (Detective Comics #460).

August:

• Ragman (Ragman #1).

September:

• Hawkgirl joins the JLA (Justice League of America #146), 
• Calculator, 
• Black Spider (Detective Comics #463), 
• Atomic Skull (Superman #303).

1977

April:

• Black Lightning, Tobias Whale (Black Lightning #1).

May:

• Rupert Thorne, Dr. Phosphorus (Detective Comics #469),
• Faora (Action Comics #471).

June:

• Shade, the Changing Man (Shade the Changing Man #1),
• Silver St. Cloud (Detective Comics #469).

July: Black Manta kills Aquababy (Adventure Comics #452).
August:

• Rotman is revealed alive, new Doom Patrol (Showcase #94).
• Professor Hugo Strange returns (Detective Comics #471).

October: Taz, Icemaiden (Super Friends #7).

November: Huntress (DC Super Stars #17).
December: Deadshot returns (Detective Comics #474).  

1978

February: Madame Xanadu (Doorway to Nightmare #1).

March:

• Firestorm (Firestorm, the Nuclear Man #1).

Spring:

• Superman vs. Muhammad Ali (Superman vs. Muhammad Ali).

July:
Aquababy
Clayface III (Detective Comics #478).

August:

• The Atom reveals his secret identity to Jean Loring and they marry (Justice League of America #157.

December:

• Zatanna joins the JLA (Justice League of America #161).

1979

April: Maxie Zeus (Detective Comics #483).
July: Iris West dies (Flash #275).
October:

• Fire (Super Friends #25),
• Viking Commando (All-Out War #1).

1980

September: The Crime Doctor (Detective Comics #494).
October:

• Starfire, Cyborg (DC Comics Presents #26).

November:

• Mongul (DC Comics Presents #27),
• the Creature Commandos (Weird War Tales #93),
• Gregorian Falstaff (Batman #317).

June:

Full membership of the Justice League of America, bu José Luís García López.

• Firestorm joins the JLA (Justice League of America #179).

1981

January: Electrocutioner (Batman #331).
March: The Dibnys solve the mystery of Edga Allan Poe's death (Detective Comics #500),
May: Arisia (Tales of the Green Lantern Corps #1),
July: Vixen (Action Comics  #521), the Snowman (Batman #337),
December: Insect Queen of Earth-2 (Superman Family #213).

1982

January:

• Ch'p (Green Lanten #148),
• the real Mad Hatter debuts on Earth-1 (Detective Comics #510),
• Dagger (Batman #343).

February:

• Mayor Hamilton Hill,
• Mirage (Detective Comics  #511). 

March: Arion (Warlord #55).
June:

• Lobo (Omega Men #3).

July: Harbinger (New Teen Titans Annual #2).
October: General Sunderland (Swamp Thing #6).

1983

February: Killer Croc (Detective Comics #523).

March: Jason Todd (Batman #357).

April:

• Amethyst and Gemworld (Legion of Super-Heroes #298).

July:

• Nightwing (Tales of the Teen Titans #44).

August: Nocturna (Detective Comics #529).
September:

• Infinity Inc., Jade (All-Star Squadron #25).
• The Atom discovers his wife, Jean Loing, cheating on him, they divorce and he ends up lost in the Amazon jungle as the defender of a race of tiny yellow people (Sword of the Atom #1). 

December: Vigilante II (New Teen Titans Annual #2).

1984

February: Javelin (Green Lantern #173).

March: Jason Todd becomes Robin (Batman #368).

June:

• Constantine (Swamp Thing #37),
• Blue Devil (Fury of Firestorm #24),
• Wrath (Batman Special #1).

August:

• The Justice League Satellite is destroyed. The Martian Manhunter returns (Justice League of America #229).
• Black Mask (Batman #386).

October:

• Steel III, Vibe, Gypsy, Dale Gunn. "Justice League Detroit": Aquaman disassembles the JLA and creates a new one with only full-timers: the Elongated Man, Zatanna, the Martian Manhuter and himself as leader. Sue moves permanently with them, they added Vixen, Steel III and Vibe and got new headquarters in Detroit, mantained by Dale Gunn. Sue (Justice League of America Annual 32).

1985

April: Crisis on Infinite Earths starts.
May: Bolphunga, Mogo (Green Lantern #188).

1986

March: Crisis on Infinite Earths, the original Multiverse and the silver age of DC Comics end.
July: Sue gets a new costume for the Elongated Man to receive the Modern Age (Justice League of America #252).

Notes: I used cover dates for this list (wich means you have to substract a couple of months).
Font types are modified according to the character.

• Important character,
• Character with an equivalent on Earth-2,
• Character with an Earth-2 double,
• Might have Earth-2 double, but their debut date makes it abiguous,
• Crossed-over descendant of an Earth-2 character,
• Created in other media first.
• Not tied to the DCU yet,
• Related to the Elongated Man.  

Go back to:

• The Elongated Man and the Silver Age Timeline!, Part I: Pre-Classic (1947 - 1956).
• The Elongated Man and the Silver Age Timeline!, Part II: Classic (1956 - 1969).
• The Elongated Man and the Silver Age Timeline!, Part III: Post-Classic (1969 - 1973).  

Related articles:

• Survivors of the Golden Age! - This article will help you identify character counterparts between Earth-One and Earth-Two.