Who was the President of the United States during the Great Depression and WWII?

Franklin D. Roosevelt served as the President of the United States during both the Great Depression and World War II, making him a key figure in American history during these significant events. He was first elected in 1932, and his New Deal policies were implemented to address the economic crisis of the Great Depression, focusing on recovery and reform of the financial system while providing relief to millions of struggling Americans.

Roosevelt's leadership continued as he steered the nation through World War II after the attack on Pearl Harbor in 1941, playing a critical role in formulating strategies for victory alongside Allied leaders. His presidency marked a profound transformation in the government's role in the economy and society, earning him a lasting legacy. This timeframe was pivotal in shaping modern America, further solidifying why he is the correct answer to the question.

The other figures listed did not serve during this specific overlap. Theodore Roosevelt was President before the Great Depression, Harry S. Truman succeeded FDR after his death in 1945, and Lyndon B. Johnson was president during the 1960s, well after World War II had ended.