The president of the United States during both the Great Depression and World War II was Franklin D. Roosevelt. He assumed office in 1933 at the height of the Great Depression and led the nation through this severe economic crisis by implementing the New Deal programs aimed at relief, recovery, and reform. Roosevelt was then president throughout World War II until his death in 1945, guiding the country through the war effort after the attack on Pearl Harbor in 1941. He was elected to four terms, serving from 1933 to 1945, making him the longest-serving U.S. president in history