While FDR had many things in place to attempt to bring us out of the Depression the start of World War II was the catalyst to getting the economy going and ending the depression. While Roosevelt had a plan in place it would have been a very slow process without the war.
In John Dos Passos's American Trilogy, the author used a technique called the "headlines"; that is, Dos Passos placed newspaper headlines in between chapters. For one part of one of the three novels, he used the headline about J. P. Morgan having loaned the U. S. Government vast sums of money in order for it to pull itself out of trouble.
I agree that the Great Depression ended only because of the outbreak of World War II. Franklin Roosevelt is often given credit for ending the Depression; however this is not the case. He did give the American people hope, and perhaps prevented the nation from descending into chaos. However, with the bombing of Pearl Harbor, and the declaration of war by Italy and Germany on the U.S. the entire economy was geared toward production of war goods. The phrase most historians use is "full mobilization." This only happened one time before--during World War I. Unemployment ended, and the country got back on its feet again. So, if you want to give someone credit for ending the depression, that credit should go to Adm. Yamamoto, Premier Hediki Tojo, and of course Hitler and Mussolini.
Although Franklin D. Roosevelt is often given credit for ending the Great Depression through his New Deal programs, historians argue that the Depression was only ended by WWII. As the US started building up to help the Allies and, eventually, to participate in WWII, the Depression ended.
In Europe, World War II started in 1939. It was not long after that that the US started to provide the Allies with war materiel. That helped put people back to work in factories. At the same time, beginning in late 1940, the US started drafting men into the armed forces. This further cut down on the ranks of the unemployed. Once the US fully joined the war (in late 1941), the economy started going at full blast as millions of men went off to war and huge amounts of war materiel were needed.
The overall answer, then, is that WWII ended the Great Depression.
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