Question

What event triggered the Great Depression?

Answer 1

It was triggered in large part by a sudden crash of the American stock market on October 29, a day widely known as Black Tuesday. 

Answer 2

The Great Depression was a worldwide economic downturn that began in the fall of 1929 and did not end in many places until the Second World War. It was triggered in large part by a sudden crash of the American stock market on October 29, a day widely known as Black Tuesday.

It is also thought that the Great Depression was triggered by the First World War.