In the 1920s, sculptor Gutzon Borglum and President Calvin Coolidge selected George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln to appear on Mount Rushmore—it later became an iconic symbol of presidential greatness.In political studies, surveys have been conducted in order to construct historical rankings of the success of individuals who have served as President of the United States. Ranking systems are usually based on surveys of academic historians and political scientists or popular opinion. The rankings focus on the presidential achievements, leadership qualities, failures and faults.