On October 31, 1864, Abraham Lincoln admitted Nevada to the Union to aid in the Civil War. American Indians may have lived in the Nevada region more than 20,000 years ago, making this area home to some of the earliest Indians in the United States. In southern Nevada, Indians left picture writing on rocks that date back thousands of years. Nevada tribes include the Pueblo, Mohave, Paiute, Shoshone, and Washoe.