During the interwar period, J.P. Morgan was the most important bank in the world and at the crossroads of US politics, international relations and finance. In J.P. Morgan & Co. and the Crisis of Capitalism, Martin Horn brings us the first in-depth history of how J.P. Morgan responded to the greatest crisis in the history of financial capitalism, shedding new light on the Great Depression, the New Deal, and the coming of World War II. Horn shows how J.P. Morgan & Co as a business responded to the 1929 Crash and the Depression, including its part in the New York Stock Exchange Crash, arguing that the Morgan partners misread the seriousness of the crash. He also offers new insights into the interactions of politics and finance, exploring J.P. Morgan’s relationship with the Hoover administration and the bank’s clash with Roosevelt over New Deal legislation.