Though they played in the years before Rube Foster formed the first Negro League, the St. Paul Gophers and their bitter crosstown rivals, the Minneapolis Keystones, had the talent, bench depth, and determination to rival many of those later, better known teams. (The Gophers, in fact, beat Chicago's celebrated Leland Giants in 1909, laying claim to blackball's western championship.) Focusing on these two clubs, author Peterson lays out the early...