In 1880, horse-drawn carriages rumbled through Tucson and pioneering prospectors plied the Arizona mountains in search of copper, gold and silver. In the center of Tucson, Washington M. Jacobs opened an assay office at the former 30 S. Main St., providing ore- and metals-testing services to miners eager to cash in their claims in the town's more than 25 saloons and gambling houses. Statehood was still 32 years away.