The leaders of the country who were elected president during the Depression & WW2 Era, and helped to make United States History, were Herbert Hoover and Franklin D Roosevelt.

President Herbert Hoover and the Depression Era: Herbert Hoover Presidency (1929-1933)
Important events in United States History during the presidency of Herbert Hoover includes the Wall Street Crash, The Bonus Army March, The Great Depression and the Hoover Dam.

Franklin D Roosevelt Presidency (1933-1937) & (1937-1941) & (1941-1945) & (1945)
Important events in United States History during the presidency of Franklin D Roosevelt includes the 21st Amendment added to the Constitution, The New Deal, Pearl Harbor and the US entry into World War 2.

President Franklin Roosevelt and the events of WW2

President Harry S. Truman and the End of WW2
President Roosevelt died on April 12, 1945 and Harry S. Truman immediately assumed the presidency during this critical time in US history. Important WW2 events in United States History during the presidency of Harry S Truman.

The events of Truman's presidency move on to the Cold War Era.

United States History
The following link provides access to all the most important events of each of the presidencies in the history of the United States of America.