The design of the Justice League Columns Collection has 6 vertical panels creating a large square. Each vertical panel shows 6 of the seven original DC Comics super heroe members of the Justice League: Superman, Batman, the Flash, Green Lantern, Wonder Woman, and Martian Manhunter.

The team appeared first in The Brave and the Bold #28 (March 1960) comic book story that was conceived by writer Gardner Fox as a revival of the Justice Society of America, a similar team from DC Comics in the late 1940s.

To read about the Justice League as presented in DC Comics go to this DC Comics post.

Or this wikipedia page titled: Justice League 

Or this post titled A (brief) history of the Justice League – in all its incarnations by John Jackson Miller / November 15, 2017 that follows a time line from 1960 to the present.