Churchill County was established in November of 1861, three years prior to statehood. Fort Churchill had already been built earlier in 1861. According to the Fort Churchill State Park website, "An integral part of the history of Nevada and the American West, Fort Churchill was built in 1861 to provide protection for early settlers and guard Pony Express mail runs." Fort Churchill and Churchill County were named after a Mexican-American war hero and Brigadier General Sylvester Churchill. There were many towns and camps in Churchill that developed around mining. The first county seat of Churchill was located at Buckland's Station. Buckland's is now a part of Lyon County. In 1864, the county seat was moved to a booming mining area called La Plata. By 1867, La Plata was in decline. The county seat was then moved to Stillwater in 1868. Unlike La Plata, Stillwater was known for its agricultural operations. By 1904, the actual town of Stillwater had declined. Agriculture in the surrounding area outside of Stillwater still exists today. The county seat was then moved to Fallon, where it remains today. According to the 2020 U.S. Census, the population of Churchill County was 25,516.