The Great Depression was a period of worldwide economic crisis between World War I and World War II. It began with the Wall Street Crash of 1929 and spread around the globe. Overproduction, lagging demand, and an overexpansion of consumer credit led economies worldwide into crisis as demand could not keep up with supply. Franklin D. Roosevelt introduced his New Deal programs in the U.S. to revive the economy, while Adolf Hitler rose to power in Germany to lead a desperate population during this difficult time.