before the memorial was carved, the native lakota indian tribes called the mountain "six grandfathers". later, the mountain was named after charles e. rushmore, a well-known later, after an expedition in 1885. the memorial was carved to help increase tourism in the black hills, where the mountain was. doane robinson first formed the idea in 1923. robinson convinced many influential people in the united states government to build the memorial. congress soon allowed construction to begin.