In 1847, Dr. Robert Semple contracted to provide ferry service from Martinez to Benicia, which for many years was the only crossing on the Carquinez Strait. By 1849, Martínez served as a way station for the California Gold Rush. The town was laid out in 1849 by Col. William M. Smith and named for Martinez. It became the county seat in 1850, but could not incorporate at the time because it lacked the 200 registered voters required, and only became a city in 1876.