Having successfully re-introduced a number of their Golden Age superhero characters (Flash, Green Lantern, etc.) during the late 1950s, DC Comics asked writer Gardner Fox to re-introduce the Justice Society of America. Fox, influenced by the popularity of the National Football League and Major League Baseball, decided to change the name of the team from Justice Society to Justice League. The Justice League of America debuted in The Brave and the Bold #28 (1960), and quickly became one of the company's best-selling titles. Fox wrote virtually all of the League's adventures during the 1960s, and artist Mike Sekowsky pencilled the first five years.

As with the Justice Society, the concept of the Justice League was simple: to include all of DC's most popular characters in one book (hence the original lineup included Superman, Batman, Aquaman, the Flash, Green Lantern, and Wonder Woman). JLA's early success was indirectly responsible for the creation of the Fantastic Four, and by extension the entire Marvel universe. In his autobiography Stan Lee relates how, during a round of golf, DC publisher Jack Liebowitz mentioned to Marvel-Timely owner Martin Goodman how well DC's new book (Justice League) was selling. Later that day Goodman told Lee to come up with a team of superheroes for Marvel; Lee and Jack Kirby produced the Fantastic Four.

The Justice League operated from a secret cave outside of the small town of Happy Harbor. Teenager Snapper Carr tagged along on missions, and was both the team's mascot and an official member. Snapper, noted for speaking in beatnik dialect and snapping his fingers, helped the League to defeat giant space starfish Starro the Conqueror in the team's first appearance. In Justice League of America #77 (December 1969), Snapper was tricked into betraying the cave headquarters' secret location to the Joker, resulting in his resignation from the team.