The Mount Rushmore National Monument is a sculptural complex in the rock located in South Dakota, on the Black Hills mountain massif, formed by enormous granite blocks. Also known as Tȟuŋkášila Šákpe in Lakota, or Six Grandfathers, it was the sculptor Gutzon Borglum who created the premises for the realization of the work, supervising the execution of the project from 1927 to 1941 with the help of his son, Lincoln Borglum.
Following the dictates of Borglum, the sculptures, whose faces reach the size of 18 m, depict the faces of presidents George Washington (1732-1799), Thomas Jefferson (1743-1826), Theodore Roosevelt (1858-1919), Abraham Lincoln (1809-1865). The choice fell on the four presidents because they respectively represented the birth, growth, development and stability of the nation. The memorial park covers a vast area of 5.17 km² and the current conformation of the mountain reaches an altitude of 1,765 m a.s.l.
It is to the South Dakota historian Doane Robinson that the hypothesis of sculpting the likenesses of famous people in the mountains of the Black Hills is recognized, born in order to promote tourism in the region. Initially ready to sculpt the Needles, granite pillars eroded in the form of very characteristic columns, Gutzon Borglum rejected this prospect due to the poor quality of the rocks and the strong opposition of the Lakota, who considered the Black Hills a sacred site included in the reserve of Great Sioux. Following a controversial Black Hills takeover process, the United States saw a surge of interest in the region when gold was discovered.