When WWI breaks out previously best friends in their New York neighborhood, The Schultz and Du Bois families, take opposite sides in the conflict. When their youngest Little Johnnie Du Bois and Heinie Schultz, backed up by their "allies," decide to fight it out in a vacant lot a battle royal takes place between the two families. But by this time the Schultze’s' eldest son Fritz and the Du Bois’ pretty daughter Marie have fallen in love so when they embrace in front of the families all agree to put their differences aside since "First and foremost we're all good Americans."