As with their compatriots Superman, Batman and Green Lantern, each Flash was a founding member of his world's premier protectors. Barry Allen aka the Flash continued his association with the Justice League throughout its history, up until its dissolution following a Martian invasion. At one point, due to his inadverdent slaying of his foe Professor Zoom, the Flash was nearly evicted from the League, although they elected to keep him as a member. Still, he left shortly thereafter to be reunited with his wife in another century.
Jay Garrick aka the Flash participated during the first few cases of the Justice Society of America, being its first chairman, after which he takes of leave of absence to become the team's third honorary member. However, a few years later he returned and was hencforth an active member up until its dissolution in 1951, and rejoined it after it was revived a decade later. From then on, Jay was virtually inseperable from his Society comrades, even training a new generation of heroes.