Black Thursday. The Stock Market crash ended the prosperity of the Roaring 20s. Millions were out of work. This was just seven months after America's 31st president took office. His name was Herbert Hoover, born this day, Aug. 10, 1874. The son of a Quaker blacksmith, he studied at Stanford and became a world-renowned engineer before entering politics. In the Great Depression, President Hoover stated: "American life is builded ... upon that fundamental philosophy announced by the Savior 19 centuries ago. ... [It] cannot survive with the defense of Cain, 'Am I my brother's keeper?'"