After gold was discovered at Sutter's Mill in 1848, thousands made the journey to California, including daguerreotypists who established studios in cities and towns and ventured into the gold fields in specially outfitted photographic wagons. The California gold rush was the first major event in American history to be documented in depth by photography, and the 150 remarkably well-preserved images here include vivid portraits of the hardy men and women of various nationalities who made the trek, and glimpses of the ramshackle towns that would become major cities in the American West.