The Great Depression was a severe worldwide economic depression that took place after 1929. The timing varied across nations; in most countries it started in 1929 and lasted until the late 1930s. It was the longest, deepest, and most widespread depression of the 20th century. The depression originated in the United States and became worldwide news with the stock market crash of 29 October 1929 (known as Black Tuesday). Between 1929 and 1932, worldwide GDP fell by an estimated 15%. By comparison, worldwide GDP fell by less than 1% from 2008 to 2009 during the Great Recession. Some economies started to recover by the mid-1930s. However, in many countries, the negative effects of the Great Depression lasted until the beginning of World War II.