Who was President during the Great Depression and World War II?

The president during the Great Depression and World War II was Franklin D. Roosevelt. He took office in 1933, amidst the economic turmoil of the Great Depression, and implemented a series of programs and reforms known as the New Deal aimed at providing relief, recovery, and reform to restore the economy. His leadership during this challenging time was pivotal in shaping government response to economic crisis.

Roosevelt also served as president throughout World War II, from 1941 when the United States entered the conflict after the attack on Pearl Harbor, until his death in 1945. He played a crucial role in mobilizing the nation for war and was a key figure in the Allied Powers' strategy, helping to coordinate efforts among various nations to defeat the Axis Powers.

The other figures mentioned held offices during different periods: Richard Nixon served during the late 1960s to early 1970s, Harry S. Truman succeeded Roosevelt in 1945 and led after the war, and John F. Kennedy was president from 1961 until his assassination in 1963. Each of these presidents faced unique challenges distinct from those of Roosevelt's era, which is why Franklin D. Roosevelt is the correct answer in the context of both the Great Depression and World War II