Harry S. Truman (May 8, 1884 – December 26, 1972) was the 33rd president of the United States from 1945 to 1953, succeeding upon the death of Franklin D. Roosevelt after serving as vice president. He implemented the Marshall Plan to rebuild the economy of Western Europe, and established the Truman Doctrine and NATO. He remained an active reservist until the early 1940s. Truman volunteered for active military service during World War II, but was not accepted, partly because of age, and partly because President Franklin D. Roosevelt desired Senators and Congressman who belonged to the military reserves to support the war effort by remaining in Congress, or by ending their active duty service and resuming their Congressional seats. He was an inactive reservist from the early 1940s until retiring as a colonel in the then redesignated U.S. Army Reserve on January 20, 1953.