Western representatives successfully argued that western miners and prospectors were performing valuable services by promoting commerce and settling new territory. In 1864, Congress passed a law that instructed courts deciding questions of contested mining rights to ignore federal ownership, and defer to the miners in actual possession of the ground. The following year, Congressional supporters of western miners tacked legislation legalizing lode (hardrock) mining on public land onto a law regarding ditch and canal rights in California, Oregon, and Nevada. The legislation, known as the "Chaffee laws" after Colorado Territorial representative Jerome B. Chaffee, passed and was signed on July 26, 1866.