Who was the President of the United States when the US entered World War II?

Franklin D. Roosevelt was President of the United States when the country entered World War II. After Japan attacked Pearl Harbor on December 7, 1941, Roosevelt asked Congress for a declaration of war the following day, formally bringing the United States into the conflict.

Roosevelt had already supported the Allied powers through measures such as Lend-Lease, which supplied Britain, the Soviet Union, China, and other nations with weapons and materials. Before Pearl Harbor, however, the United States was not formally at war with the Axis powers.

A common mix-up is with Woodrow Wilson, who was president when the United States entered World War I in 1917. Harry S. Truman became president after Roosevelt died in April 1945 and authorized the atomic bombings of Hiroshima and Nagasaki. Dwight D. Eisenhower was a leading Allied general during World War II and became president only in 1953.