Prior to the arrival of European settlers, Alabama was populated by Cherokee, Creek, Choctaw, and Chickasaw Indians, which were known as the Civilized Tribes on account of their relatively advanced societies.De Soto was the first white man to explore the interior of present day Alabama. The first significant settlement was accomplished by French colonists, who arrived in 1702 and established a settlement in 1711 at what is now Mobile. The French lost their North American possessions to the British in 1763. The British in turn granted the region around Mobile back to Spain, which lost it to the United States in the War of 1812. Alabama was organized as a territory in 1817 and entered the Union as the 22nd state in 1819. Federal troops invaded the last remaining Indian territory in the northeast section of the state in 1838 and by 1840, the Indians had nearly all been driven west of the Mississippi. As a result of the election of Abraham Lincoln in 1860, Alabama seceded from the Union on January 11, 1861, and declared itself the Republic of Alabama. In February, a convention of delegates from other Southern states formed the Confederate States of America, with Montgomery as its capital. The need for coal during the Civil War brought about the acceleration of its development and production in such towns as Hoover, which had been built above the Cahaba Coal Fields in Jefferson County. After its defeat by Union forces, Alabama was subjected to Reconstruction until 1873. In the years that followed, coal mining and steel manufacturing became the state's leading industries, with Birmingham as its center. During the Great Depression, the Tennessee Valley Authority developed dams that produced electricity and controlled flooding. Following World War II, one of the nation's primary missile development centers existed at Huntsville. An important turning point of the civil Rights Movement took place in Montgomery in 1955, when Martin Luther King, Jr. led a boycott of buses to protest segregation. Integration of the University of Alabama was strongly opposed by Governor George Wallace, who became a folk hero to segregationists for defying federal orders in 1863 to integrate it. Like Governor Faubus of Arkansas, Wallace used that act to solidify support among white voters and eventually gained a national following.