Question

What caused the Depression of 1920-21?

Answer 1

The Depression of 1920–21 in the United States was brief relative to the Great Depression of a decade later, but it included a remarkably sharp price deflation.[1]

In this depression prevailed the old-fashioned view that government should keep taxation and spending low and reduce the public debt. The economy recovered swiftly, especially when compared with the Great Depression.[

http://wiki.mises.org/wiki/Depression_of_1920%E2%80%9321