Tennessee is one of the 50 states of the United States. What is now Tennessee was initially part of North Carolina, and later part of the Southwest Territory. It was admitted to the Union on June 1, 1796, as the 16th state. Tennessee would earn the nickname "The Volunteer State" during the War of 1812, when many Tennesseans would step in to help with the war effort. Especially during the Americans victory at the Battle of New Orleans in 1815. The nickname would become even more applicable during the Mexican–American War in 1846, after the Secretary of War asked the state for 2,800 soldiers, and Tennessee sent over 30,000 volunteers. Tennessee was the last state to formally leave the Union and join the Confederacy at the outbreak of the American Civil War in 1861. With Nashville occupied by Union forces from 1862, it was the first state to be readmitted to the Union at the end of the war. During the Civil War, Tennessee would furnish the second most soldiers for the Confederate Army, behind Virginia. Tennessee would also supply more units of soldiers for the Union Army than any other state within the Confederacy, with East Tennessee being a Unionist stronghold. During the Reconstruction era, the state had competitive party politics, but a Democratic takeover in the late 1880s resulted in passage of disenfranchisement laws that excluded most blacks and many poor whites from voting, with the exception of Memphis. This sharply reduced competition in politics in the state until after passage of civil rights legislation in the mid-20th century. During the early 20th century, Tennessee would transition from an agrarian economy based on tobacco and cotton, to a more diversified economy. This was aided in part by massive federal investment in the Tennessee Valley Authority created by Franklin D. Roosevelt's New Deal, helping the TVA become the nation's largest public utility provider. The huge electricity supply made possible the establishment of the city of Oak Ridge to house the Manhattan Project's uranium enrichment facilities, helping to build the world's first atomic bombs. In 2016, the element tennessine was named for the state, largely in recognition of the roles played by Oak Ridge, Vanderbilt University, and the University of Tennessee in the element's discovery. Prehistory Paleo-Indians are believed to have hunted and camped in what is now Tennessee as early as 12,000 years ago. Along with projectile points common