The Pre-Teen Braves is an organizations for boys who learn how to live like Indians do.
After Bart and Milhouse were captured by police inside of Ned's house, Bart was no longer allowed to play with Milhouse. Bart was made to join the Pre-Teen Braves along with other boys and Homer became their tribe leader. However, he didn't know how to lead an Indian tribe, so Marge took over.
Marge and the boys did many interesting activities, for example meeting a Native American (Mohican) who showed them a field that needed to restoration. The Pre-Teen Braves came to a field again to clean it up, only to discover that the Cavalry Kids, an organization of which Milhouse and his father are members, had already done the job.
The two groups went to the war and tried to outdo each other in doing good. When they both wanted to become batboys at a Springfield Isotopes game, they had to redouble their efforts for their candy sales. The Pre-Teen Braves filled the Cavalry Kids' candy bars with laxatives and believed they are going to win.
Unfortunately for them, the senior citizens liked those bars and the Cavalry Kids won. At the Springfield Isotopes game, the Cavalry Kids were delayed from arriving when Bart and Homer placed a sign that said "free VIP parking" and the Pre-Teen Braves took their place singing their version of the national anthem. The crowd became angry by the version and when the real Cavalry Kids arrived, a fight broke out between everyone at the stadium. During this fight, Lenny revealed that he was once a Pre-Teen Brave. Marge began to cry. when the image of her was shown on the Jumbotron, the fighting ended. The Sea Captain suggested not to sing a "hymn to war, like our National Anthem, but a sweet, soothing hymn like Canada's National Anthem". Everyone joined their hands to form a maple leaf and sang O Canada.