Justice League of America Vol 2

One year after the events of Infinite Crisis, Superman, Batman, and Wonder Woman reunite in the Batcave to re-form the League in Justice League of America #0, the kick-off Justice League of America Vol 2 by  Brad Meltzer and  Ed Benes. The series featured a roster which included Green Lantern (Hal Jordan), Black Canary, Red Arrow (Green Arrow's former sidekick), Red Tornado, Vixen, Black Lightning, and Hawkgirl. The first arc of the series focused upon Red Tornado and pitted the team against a new intelligent incarnation of Solomon Grundy and the rebuilt Amazo. The new incarnation of the team has two main headquarters, linked by a transporter. The first site is The Hall, which in mainstream DC Universe is a refurnished version of the Justice Society of America and the All-Star Squadron's former headquarters located in  Washington, D.C. Black Canary is elected as the first official Chairperson after the fight against Amazo and Solomon Grundy, and led both the Justice League and Justice Society in a complex quest to reunite time-lost members of the pre-Crisis  Legion of Super-Heroes, who had been sent back in time to free both  Bart Allen and Flash from the other dimensional realm of the  Speed Force. Meltzer left the series at the end of issue #12, with one of his subplots ( Per Degaton, a pre-nuclear fire mutation version of Despero, and a circa 1948 version of the  Ultra-Humanite gathering for an unknown plot) resolved in the pages of Booster Gold.

Dwayne McDuffie took over the writing job with the Justice League Wedding Special and the main book with issue #13. Due to DC Comics seeking to launch a spin-off Justice League book led by Hal Jordan, the character was removed from the main League series and replaced by John Stewart. Firestorm also joined the roster, with the series entering into a series of tie-in storylines towards Countdown to Final Crisis, with the arrest of a large number of supervillains (gathered by Lex Luthor and Deathstroke to attack the League on the eve of the wedding of Black Canary and Green Arrow) setting up the  Salvation Run tie-in miniseries. Also, roster members Red Tornado and Geo-Force were written out. McDuffie's run received mixed reviews and negative fan response due to fan favorite Hal Jordan's removal in favor of Stewart. Jordan ended up being restored to the roster by issue #19 of the series, only to be removed once again by issue #31 once Justice League: Cry for Justice was completed and ready to be shipped.

Issue #21 saw the return of Libra and the Human Flame, setting up their appearances in  Final Crisis. Later issues would resolve issues involving Vixen's power level increase and see the integration of the Milestone Comics characters the Shadow Cabinet and Icon, who fought the Justice League over the remains of the villainous Doctor Light. The group suffered greater losses during Final Crisis with the deaths of Martian Manhunter and Batman, leading to Green Arrow and Hal Jordan forming their own splinter Justice League group to hunt down the men responsible for arranging Martian Manhunter's death (Black Canary herself has also sent John Stewart and Firestorm after Human Flame, as seen in the Final Crisis Aftermath: Run! miniseries).

Hal's decision to form his own group, combined with the rest of the roster leaving the group due to their own personal issues, has resulted in a new League roster of Black Canary, Firestorm, John Stewart, Zatanna, Vixen, and the heroic female Doctor Light. Later, Black Canary tries to disband the League, believing it to be too weak with its current, shaky roster. It is implied by the comments of Vixen and Firestorm that the team took this more as a resignation on her part. Thus, Vixen has assumed command of the League.

Len Wein wrote a three-part fill-in story for Justice League of America that ran from #35 to #37. McDuffie was fired from the title before he could return, after discussion postings to the DC Comics message board, detailing behind-the-scenes creative decisions on his run, were republished in the rumor column "Lying In The Gutter". James Robinson was announced as the new Justice League of America writer.

Following the events of "Cry for Justice", the JLA is once again decimated with Hal Jordan being forced to rebuild the League, with Green Arrow, the Atom, Batman, Mon-El,  Donna Troy, Cyborg, Doctor Light, Starfire,  Congorilla, and the Guardian.

At the end of issue #43, the majority of the new members leave for various reasons. Mon-El and the Guardian leave after Mon-El returns to the future, Black Canary returns to the Birds of Prey, Starfire leaves to join the R.E.B.E.L.S., Green Lantern leaves due to his new status after  Blackest Night, and Green Arrow is forced to leave due to his fugitive status. James Robinson revealed this was due to him having second thoughts about his decision to use so many characters, and revealed that the team will have a different roster in the coming months. He confirmed that to replace the departed members, Jade and Jesse Quick will be joining. He later revealed that Cyborg will remain with the team in a reduced capacity, and will be given his own co-feature storyline for issues 48–50.

Various origins of the Justice League
In a story told in flashback in 1962's Justice League of America #9, Earth was infiltrated by the Appelaxians. Competing alien warriors were sent to see who could conquer Earth first to determine who will become the new ruler of their home planet. The aliens' attacks drew the attentions of Superman, Batman, Wonder Woman, Flash (Barry Allen), Green Lantern (Hal Jordan), Aquaman, and  Martian Manhunter. While the superheroes individually defeated most of the invaders, the heroes fell prey to a single competitor's attack; only by working together were they able to defeat the competitor. For many years, the heroes heralded this adventure as the event that prompted them to agree to pool resources when confronted with similar menaces.

Years later, however (as revealed in Justice League of America #144), Green Arrow uncovered inconsistencies in League records and extracted admissions from his colleagues that the seven founders had actually formed the League after the Martian Manhunter was rescued from Martian forces by the other six founders, along with several other heroes including Robin, Robotman, Congo Bill/Congorilla, Rex the Wonder Dog, and even  Lois Lane. Green Lantern participated in this first adventure solely as Hal Jordan, due to the fact that he had yet to become the costumed hero at that time (the biggest inconsistency Arrow found, as they celebrated the earlier incident's date, while recounting only the later one's events). When the group formalized their agreement, they suppressed news of it because of anti-Martian hysteria (mirroring the real-world backdrop of Martian scares and anti-communist hysteria of the 1950s). Because the League members had not revealed their identities to each other at the time, they did not realize that Jordan and Green Lantern were one and the same when he turned up in costume during the event described in #9. While most subsequent accounts of the League have made little mention of this first adventure, the animated Justice League series adapted this tale as the origin of the League as well.

1989's  Secret Origins #32 updated Justice League of America #9's origin for Post-Crisis continuity. Differences included the inclusion of the original Black Canary as a founding member and the absence of Batman, Wonder Woman, and Superman (the 1960s time frame was retained, but the post-Crisis versions of DC's three biggest stars were young and early in their careers in the late 1980s). Additionally, while Hal Jordan served as the public face of the Justice League, this iteration of the League's origin cast the Flash as the team's unofficial leader, since it was Allen who usually came up with the plans that best utilized everyone's powers. 1998's JLA: Year One limited series, by  Mark Waid,  Brian Augustyn, and  Barry Kitson, further expanded upon the Secret Origins depiction, with the revelation that the group was secretly financed by Oliver Queen, a.k.a. the superhero Green Arrow. It also stated that Superman rejected membership into the group, leading to much animus between him and the other "founders" during the early years of the group.

In 1994's Justice League Task Force #16, during Zero Hour, an unknown superhuman named Triumph appeared. It was revealed that, in a plotline never explored before, Triumph was revealed to have been a founding member of the Justice League, serving as their leader. On his first mission with the fledgling Justice League, Triumph seemingly "saved the world", but was teleported into a dimensional limbo that also affected the timestream, resulting in no one having any memory of him. This was to explain how all the heroes ended up in Washington for their first meeting.

Further convolutions came with the issue of Batman's involvement with the League; during the 1990s, the editors of Batman sought to distance Batman from the Justice League, to the point of demanding that Batman's entire Justice League membership be removed from the group's canon. According to Christopher Priest, this "Batman was never in the Justice League" edict came down ironically after DC published Justice League America Annual #9, which featured Batman as a member of the League during its early days. The edict itself was largely haphazardly enforced; while Mark Waid had Batman proclaim to have never been a member of the League in Justice League Incarnations #7, other writers such as Grant Morrison and Keith Giffen took the stance that Batman had simply never joined the team until the Justice League International era. This edict was ultimately dropped by the early 2000s, as Batman's involvement with the League is now referenced heavily by later writers such as Brad Meltzer.

The convoluted change made to Hawkman's background in the wake of the launching of the Hawkworld ongoing series, in 1990, resulted in a retcon where the original Golden Age/Justice Society Golden Age Hawkman, Carter Hall was now a member of the team as opposed to Katar Hol (who would now not join the group until 1994's Justice League America #0). The details of how Carter Hall joined the team, would be revealed in the 2001 "Justice League Incarnations #1, with the revelation that Carter joined the team to serve as a mentor for then-young heroes.

In 2006's  Infinite Crisis #7, the formation of "New Earth" (the new name for the Post-Crisis Earth) resulted in the retcon that Wonder Woman was a founding member of the Justice League in the early days. In Brad Meltzer's Justice League of America (vol. 2) #0 (2006), it was also revealed that both Superman and Batman were founding members as well. 52 - Week 51 confirmed that the 1989 Secret Origins and JLA: Year One origins were still in canon at that time, with Superman, Batman, and Wonder Woman joining the team (consisting of Aquaman, Black Canary, Flash, Green Lantern, and Martian Manhunter) with founding members' status shortly after the group's formation. However, in various issues (particularly issue #12) of the current Justice League series, the founding members of the Justice League are shown to be: Superman, Batman, Wonder Woman, Green Lantern (Hal Jordan), Flash (Barry Allen), Aquaman, and the Martian Manhunter.