Hoover, not Franklin Roosevelt, was the founder of the policy of the “New Deal”: essentially the massive use of the State to do exactly what Misesian theory would most warn against—to prop up wage rates above their free-market levels, prop up prices, inflate credit, and lend money to shaky business positions. Roosevelt only advanced, to a greater degree, what Hoover had pioneered. The result for the first time in American history, was a nearly perpetual depression and nearly permanent mass unemployment. The Coolidge crisis had become the unprecedentedly prolonged Hoover-Roosevelt depression.
Hoover prolonged the Great Depression through government intervention and manipulation of the economy.