What was the name of the President of the United States during World War II?

The President of the United States during the majority of World War II was Franklin D. Roosevelt. He served from March 4, 1933, until his death on April 12, 1945. Roosevelt was instrumental in leading the country during the Great Depression and into World War II, providing strong, decisive leadership. His administration focused on policies and initiatives aimed at supporting the war effort, including economic production, military strategy, and international alliances.

Harry S. Truman succeeded Roosevelt and became President after Roosevelt's death, but he took office after the United States had already entered the war. Dwight D. Eisenhower was a key military leader during the war and later became President, but he was not in office during World War II itself. George Washington was the first President of the United States and served much earlier, from 1789 to 1797, long before World War II. Thus, Franklin D. Roosevelt is the correct answer as he directly led the nation through the events of the war.