Memorial that represents the first 150 years of the history of the United States of America with 60-foot (18 m) sculptures of the heads of former United States presidents (left to right): George Washington (1732–1799), Thomas Jefferson (1743–1826), Theodore Roosevelt (1858–1919), and Abraham Lincoln (1809–1865). [ 1 ] The entire memorial covers 1,278.45 acres (5.17 km