The Justice League of America formed when the Black Canary, Flash, Green Lantern, Aquaman, and the Martian Manhunter joined forces to combat an invasion by an alien race called the Appelaxians. Inspired by the wartime Justice Society the five named themselves the Justice League of America and established a secret headquarters on the U.S. east coast. They were soon joined by many other new heroes: Green Arrow, Hawkman, the Atom, and even the mysterious Batman.
As the group grew larger they eventually relocated to a sophisticated satellite in geo-synchronous orbit. The team continued through several incarnations and today remains the pre-eminent hero team on the planet, ready to tackle the most dangerous of threats to humanity and beyond from their Watchtower headquarters on the Moon. The five original members are profiled here:
The current Black Canary is the daughter of the original who served with the Justice Society in the late 1940's and early 1950's. Black Canary originally had the power to emit a powerful sonic scream but has since lost that ability. It was the Canary that convinced the other four heroes to form a permanent team.
This Flash is the second to bear the name, but his relationship (if any) to the Justice Society's Flash is unknown. Flash was one of the first new heroes to emerge after the debut of Superman. Based in Central City, the Flash used his powers of super speed to battle against evil for several years, eventually giving his life to save the Earth. Flash's former sidekick, Kid Flash, has since taken up the mantle of the Flash and serves as a member of the current Justice League.
As with the Flash, Green Lantern is the second hero to bear that name. The hero was a member of an intergalactic corps of Green Lanterns and wielded a ring powered by his will and capable of nearly any feat imaginable. Green Lantern was based in Coast City but disappeared shortly after that city's destruction. He returned years later to save the Earth during the Final Night by destroying the alien Sun-Eater and rekindling the sun at the cost of his own life. A new Green Lantern has emerged recently and also holds a place in the new Justice League.
Aquaman is from the lost undersea kingdom of Atlantis. His body has adapted to surviving in the depths of the ocean, which gives him superhuman strength and resistance on land. He can also control sea life of all kinds. Aquaman has been a member of many of the incarnations of the Justice League over the years, including the current JLA. Aquaman's real name is Orin and he is the king of Atlantis. King Orin divides his time between his duties as ruler of the Earth's oceans and his commitments as a member of the Justice League.
J'onn J'onzz, the Manhunter from Mars, is one of the last surviving members of the Martian race. Accidentally brought to Earth by a scientist decades ago, the Manhunter remained hidden for years using his shape-changing abilities to assume human guise. After the emergence of Superman, the Martian Manhunter appeared in public as a super-hero. His Martian physiology gives him superhuman strength, the power to fly, and he can fire laser-like beams from his eyes. His formidable shape-changing abilities grant him a powerful edge against his opponents, as does his telepathic ability and he also has the power to turn invisible. J'onn J'onzz remains a stalwart member of the Justice League to this day.