La Paz was a short-lived, early gold mining town along the Colorado River in La Paz County on the western border of the U.S. state of Arizona. It was the location of the La Paz Incident in 1863, the westernmost confrontation of the American Civil War. The town was settled in 1862 before Arizona was officially declared a United States territory by President Abraham Lincoln. Today it is a deserted ghost town. In 1983, long after the town was deserted, the name was adopted by the newly formed Arizona county of La Paz. La Paz is Spanish for "peace"; the town was presumably named after another earlier town named La Paz, such as La Paz, Bolivia, or La Paz, Baja California Sur.
Mountain man Pauline Weaver discovered gold in the vicinity in January 1862, starting the Colorado River gold rush. La Paz grew up in the spring of 1862 along the Colorado River to serve the miners washing placer gold in the La Paz Mining District. This district produced about 50,000 troy ounces of gold per year in 1863 and 1864. La Paz had a population of 1,500 and was a stage stop between Fort Whipple, Arizona and San Bernardino, California. The town was the county seat of Yuma County from 1864 to 1870, and as the largest town in the territory in 1863 was considered for the Arizona territorial capital. The placers were largely exhausted by 1863, but the community hung on as a shipping port and supply base until the Colorado River shifted its course westward in 1866, leaving La Paz landlocked. The shipping business was taken over by a new river town, Ehrenberg, six miles south, and after 1870 La Paz became deserted and as peaceful as its name.
Today nothing remains of La Paz except a couple of crumbling stone foundations and a historical marker.