The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in 1930 and lasted until the late 1930s or middle 1940s. It was the longest, most widespread, and deepest depression of the 20th century. In the 21st century, the Great Depression is commonly used as an example of how far the world’s economy can decline. The depression originated in the U.S.