The President of the United States when World War II started in Europe was Franklin D. Roosevelt, who held office from 1933 to 1945. Herbert Hoover was the president prior to Roosevelt, while Truman and Eisenhower served after the war began. Roosevelt led the U.S. during the majority of the conflict, which officially began in 1939. ;
Franklin D. Roosevelt was the President of the United States when World War II started in Europe on September 1, 1939. He was in office from 1933 and played a major role throughout the war. Other presidents listed, such as Herbert Hoover, Harry S. Truman, and Dwight D. Eisenhower, were not in office at that time or served after the war had begun.
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