The only U.S. president to serve four terms was Franklin D. Roosevelt. He was elected to the presidency in 1932, 1936, 1940, and 1944, navigating the country through significant events such as the Great Depression and World War II. His unprecedented tenure led to the passage of the 22nd Amendment in 1951, which limited future presidents to two terms, establishing a constitutional check on executive power. Roosevelt's leadership style and policies, particularly the New Deal, fundamentally shaped American governance and social programs, leaving a lasting legacy.