Oakland Pioneers - California - Vintage Defunct Baseball Teams - 3/4 Sleeve Raglan T-ShirtOakland's Pioneers took the field in 1879 as part of the California League, representing a city still forging its identity on the eastern shore of the San Francisco Bay. Long before the Athletics arrived, this club carried Oakland's name into organized baseball's earliest chapters. Some teams are remembered not for championships, but for being first. Part of our Defunct Baseball collection, inspired by the vintage Minor League teams of yesteryear. The