1. Mount Rushmore

2. Established in 1925, South Dakota's Mount Rushmore National Memorial commemorates the first 150 years of American history.

3. Carved into the southeast face of Mount Rushmore in South Dakota are the faces of four American presidents. The faces are from left to right of George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln. 

4. Why these guys?
Each president was chosen for his role in the nation's birth and growth. George Washington signifies the struggle for independence and establishment of the Republic. Thomas Jefferson, author of the Declaration of Independence, signifies westward expansion. Abraham Lincoln signifies the permanent union of the states and equality for all citizens. And Theodore Roosevelt stands for progressive causes such as conservation and business reform.