Likely originally created to capitalize on the success of Timely Comics’ Sub-Mariner, Aquaman was one of a handful of superheroes to survive the Golden Age going into the Silver Age. When the Justice League of America was created, he was selected as a founding member but the character oft times seemed out of place against alien invasions, outer space adventures, and battling giant monsters and robots (later, the writers of Super Friends took this flaw and shined a spotlight upon it). Still, Aquaman’s solo adventures would prove so popular they would be closely adapted for television in an also popular Filmation animated series. It’s likely the success of his solo adventures helped cement the character as a member of what became DC Comics’ flagship title. Perhaps because the character was largely left to its own devices, many advents emerged in his stories. Aquaman was one of the earliest comic characters to take on an authoritative position (elected king of Atlantis), get married, have a child, and experience tragedy when his nemesis Black Manta killed his son (leading the hero and his wife Mera to subsequently divorce). The result was a character with quite the developing chip on his shoulder.
When the Earth was threatened with war by the survivors of Mars, the human race was on the verge of extinction. However, the likes of Superman, Batman, Wonder Woman, Flash, Green Lantern, Atom, and others were unavailable (several facing a crisis on Earth-Two) leaving Aquaman to lead a ragtag team of members to stave off total annihilation. If not for the return of Martian Manhunter, all would have been lost. In response, Aquaman took over the League and expelled anyone who couldn’t operate on it full-time (leaving Martian Manhunter, Zatanna, Elongated Man, and four young recruits). With the group’s satellite destroyed by the Green Martians, the team moved back to Earth and was dubbed by fans the Detroit Justice League. In reality, DC Comics would lose its top spot in the industry in the 1970s to Marvel Comics with characters like Spider-Man and the X-Men so the League was changed to attempt to draw readers back. The experiment would fail miserably and Aquaman left the group soon after.
Aquaman went through various changes after leaving the Justice League. Such included growing long hair and a beard, ditching his traditional orange and green costume for Gladiator-inspired armor, and losing his left hand, replacing it was a harpoon head. When it was decided to return the JLA back to the Big 7, Grant Morrison used the character in new, creative ways (such as defeating a White Martian in the first arc by using his underwater telepathy to tap into some remnant of when the alien evolved from a water-dwelling creature in the brain to cause a seizure). In the series, the presence of Aquaman changed. He went from being some out of place fishman to a kingly badass who carried his weight as a midlevel tank that in the presence of water dwelling creatures was a quasi-god. Still, among the Big 7, he would seemingly be considered the weakest link and was sacrificed for a DC event. However, rumor had it with the Justice League animated series on the horizon, Aquaman was soon resurrected with new powers but he never did really rejoin the JLA. He would be killed off, replaced, and resurrected again before the event Flashpoint. Aquaman would again be a founding League member in the latest continuity.
7. GREEN LANTERN
There exists literally thousands of Green Lanterns with seven being members of the Justice League at different times. So, this position is intended as a placeholder for all of them. Hal Jordan, the first Green Lantern to join the Justice League of America and one of its founders, was one of the group’s powerhouses albeit with a major flaw being unable to affect the color yellow. While elements of the character’s “cool” qualities existed (being a test pilot in his day job), it wouldn’t be until his adventures with fellow Leaguer Green Arrow as the Hard Travelin’ Heroes that the character developed some new depth. New Lanterns would emerge, themselves originally with little depth. Guy Gardner was another clean cut good guy and John Stewart as an angry black man who later writers provided new dimensions. As years and writers passed, Jordan became a recovering alcoholic and womanizer coming to grips with the America in his mind an illusion, Gardner an insufferable prick after spending years in the Phantom Zone tortured by its prisoners and watching Jordan take his girlfriend, and Stewart lose his wife to Jordan’s ex-girlfriend to emerge as a strong leader (before being subsequently bound to a wheelchair). Kilowog, who lost his planet to the Crisis on Infinite Earths, would become an ally to the League.
With the storyline “Emerald Twilight,” the Green Lantern Corps would be wiped out and a single Lantern emerged in hapless artist Kyle Rayner (now free of the weakness to yellow). At first, fans rebelled at the character because of anger over the storyline that turned Hal Jordan into a villain. But, over time Rayner developed his own following and became quite popular. When the Big 7 was brought back, Rayner filled the slot for Green Lantern. However, rather than Jordan’s confidence and bravado, Rayner was young, inexperienced, full of self-doubt, and funny. While he sparred with the Flash Wally West at first, the two became best friends (like their predecessors) being the youngest members of the group. Rayner served with the League until becoming the godlike entity Ion (following the death of Jordan), curing John Stewart of his paraplegia and giving him a power ring to be a Green Lantern once again. Sometime later, Rayner lost his new powers and roamed the stars with Jade, the daughter of the Golden Age Green Lantern, leaving Stewart in his stead and on the team (Jade would also be given a power ring and served with Rayner on the JLA at one point).
At some point, Hal Jordan would return to life and shared the duty of Earth’s Green Lantern with Guy Gardner, John Stewart, and Kyle Rayner as Kilowog went to Oa to help reform the Corps. Stewart remained with the League, though Jordan replaced Stewart for a while following Infinite Crisis but Stewart returned providing the team two Lanterns. Hal Jordan and Green Arrow would later form a rogue Justice League team in the wake of Martian Manhunter’s death where they were joint leaders (as Black Canary disbanded the official group, the pair’s team became official by extension that eventually had to be reorganized following Blackest Night, this time under Jordan and Donna Troy). Later, Jordan would leave the team and be replaced by Jade before a new continuity formed following Flashpoint. In the new continuity, Jordan was again a founding member as Guy Gardner joined the separate Justice League International and new Earth-based Green Lantern Simon Baz joined the separate Justice League of America.