The two U.S. Presidents who held office during World War II were Franklin D. Roosevelt and Harry S. Truman. President Franklin Delano Roosevelt won the election of 1940, and he was at the helm of the nation as it prepared for and entered World War II in 1941. Roosevelt was the only U.S. president to be elected four times; he served from 1933 until 1945. Harry S. Truman was his Vice President when he died. President Roosevelt, who had been a victim of Polio early in life, died in office in April 1945. President Harry S. Truman assumed the Office of Presidency and was the president when World War II came to an end.