Mount Rushmore still disputed on the basis of the 1868 Treaty of Fort Laramie (see section "Controversy" below). Among American settlers, the peak was known variously as Cougar Mountain, Sugarloaf Mountain, Slaughterhouse Mountain, and Keystone Cliffs. It was named Mount Rushmore during a prospecting expedition by Charles Rushmore, David Swanzey (husband of Carrie Ingalls), and Bill Challis. Historian Doane Robinson conceived the idea for Mount Rushmore in 1923 to promote tourism in South Dakota. In 1924, Robinson persuaded sculptor Gutzon Borglum to travel to the Black Hills region to ensure the carving could be accomplished. Borglum had been involved in sculpting the
Mount Rushmore and secured federal funding; construction began in 1927, and the presidents' faces were completed between 1934 and 1939. Gutzon Borglum died in March 1941, and his son Lincoln took over as leader of the construction project. Each president was originally to be depicted from head to waist, but lack of funding forced construction to end on October 31, 1941. Mount Rushmore attracts more than two million visitors annually. Originally known to the Lakota Sioux as "The Six Grandfathers" (Tunkasila Sakpe) or "Cougar Mountain" (Igmu Tanka Paha), the mountain was renamed after Charles E. Rushmore, a prominent New York lawyer, during