I should explain for the conservatives who fail at US History. Six Grandfathers Mountain (Mt Rushmore) is literally in the Lakota tribe's territory. It was declared theirs as a part of the 1868 Fort Laramie Treaty.
Which the US Government took a giant dump all over once they discovered gold near there. Custer got himself and the 7th Cav killed trying to seize the land.
The Supreme Court upheld that treaty in the 80's (but the US government still hasn't given the land back).
Of course, Washington and Jefferson owned slaves. Roosevelt often said "the only good Indian is a dead Indian." And Lincoln ordered the execution of the Dakota 38 the day after he signed the Emancipation Proclamation.
Oh, and the sculptor Borglum was likely a member of the KKK.