Herbert Hoover, born to a poor Iowa family, became a millionaire as a mining engineer before he was 40 years old. He led international relief programs during World War I and later served as secretary of commerce. In 1928, he was elected president by a landslide. Then in October 1929, the stock market crashed, beginning the Great Depression. Hoover worked feverishly to stop the downward cycle, but businesses failed, unemployment increased, and Hoover was blamed. He was defeated for reelection in 1932. He later became an adviser on government organization to presidents Harry S. Truman and Dwight D. Eisenhower.