The best depression-fighting President

could be Warren Harding (via David Henderson):

With Harding’s tax and spending cuts and relatively non-interventionist economic policy, GNP rebounded to $74.1 billion in 1922. The number of unemployed fell to 2.8 million — a reported 6.7 percent of the labor force — in 1922. So, just a year and a half after Harding became president, the Roaring 20s were underway. The unemployment rate continued to decline, reaching an extraordinary low of 1.8 percent in 1926. Since then, the unemployment rate has been lower only once in wartime (1944), and never in peacetime.