Hoover adopted a typical Keynesian textbook behavior after the stock market crashed. He immediately cut the income tax rates by 1% (valid for fiscal year 1929) and began to increase federal spending, increasing it by 42% between the fiscal years of 1930 and 1932.
But in order to really assess Hoover's genuinely Keynesian credentials, it is worth remembering that this huge increase in spending occurred simultaneously with a collapse in tax revenues, resulting both from the decline in economic activity and the price deflation of the early 1930s. This combination caused the Hoover administration to generate a level of deficits hitherto unprecedented in American history, for periods of peace. And what's more interesting: the Roosevelt presidential campaign platform attacked precisely those Hoover achievements