<P> The construction of Mount Rushmore National Memorial took 14 years, from 1927 to 1941 . </P> <P> Doane Robinson of the South Dakota Historical Society wanted a monument to be built in South Dakota in order to help the economy of the state by attracting tourism . In 1923, he proposed that this monument should be built from the granite cliffs in the Black Hills of South Dakota . Senator Peter Norbeck of South Dakota approved the proposal, and federal funding helped the project . Robinson asked architect and sculptor Gutzon Borglum to sculpt and design the monument . Borglum decided to use Mount Rushmore for the sculpture, since it seemed to be the easiest and most stable of the cliffs to work on . </P> <P> Having decided on the location of the sculpture, Borglum decided to make the monument of four presidents of the United States . He chose the two most famous presidents in American history, George Washington and Abraham Lincoln . He chose Thomas Jefferson because Jefferson nearly doubled the size of the United States in the 1803 Louisiana Purchase (which included the land that became South Dakota). The last president Borglum chose was Theodore Roosevelt, suggested by President Calvin Coolidge (who insisted that at least there be two Republicans and at least one Democrat represented) because of Theodore Roosevelt's introduction of the National Park Service . </P> <P> Borglum's original design was a sculpture of each president intended to go down to their waists, but time constraints and funding only provided for their heads . Ivan Houser, father of John Sherrill Houser, was assistant sculptor to Gutzon Borglum during the early years of carving; he began working with Borglum shortly after the inception of the monument and was with Borglum for a total of seven years . When Houser left Gutzon to devote his talents to his own work, Borglum's son, Lincoln, became assistant sculptor . </P>

How did they decide which presidents to put on mount rushmore
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