What was the Great Depression? When did it occur? What events caused it? When did it end?

It was the worst economic downturn in the history of the industrialized world, it began with the stock market crash of October 1929. It lasted from 1929 to 1939

The Great Depression was a severe worldwide economic depression that took place mostly during the 1930s, originating in the United States. The timing of the Great Depression varied across nations; in most countries it started in 1929 and lasted until 1941.[1] It was the longest, deepest, and most widespread depression of the 20th century.[2] In the 21st century, the Great Depression is commonly used as an example of how far the world's economy can decline.[3]