Who was the President of USA during World War II?

Franklin D. Roosevelt led America through most of World War II, having been in office since 1933 until his passing in April of 1945. Franklin D. Roosevelt led America through the beginning of WWII, while Harry S. Truman took over in 1945 to finish up the rest of the war. FDR, the 32nd President of America, served America through the Great Depression and most of WWII, from 1933 to 1945, including when America first joined World War II, as it did on December 7, 1941, when Pearl Harbor was bombed.