Harry Truman served as President from 1945 to 1953. He took office after FDR's death and faced many challenges both domestic and foreign. Domestically, he worked to transition the economy from wartime to peacetime and passed policies like the GI Bill and civil rights initiatives. Internationally, his administration dropped atomic bombs on Japan, established the UN and NATO, pursued containment of communism through the Truman Doctrine and Marshall Plan, and engaged in the Korean War.