Five of Earth’s greatest heroes, The Flash, Green Lantern, Aquaman, Black Canary and The Martian Manhunter, are brought together to battle a common enemy and form the Justice League of America.

JUSTICE LEAGUE OF AMERICA #9
Originally published in Feb 1962

The origin of the first Justice League of America from the Silver-Age of comics. The Justice League of America recalls the time they battled deadly aliens capable of transforming the heroes into trees.