He  served as the Vice President to Franklin Delano Roosevelt ⚰  only 82 days in 1945 before succeeding to the presidency following President Roosevelt’s sudden death. 
Germany surrendered only a few weeks into his presidency, but the war with Imperial Japan carried on. While still controversial to this day, Harry S. Truman forced their surrender by approving the use of atomic bombs in Hiroshima and Nagasaki. He saw it as a necessary evil, avoiding additional future invasions and sparing the lives of hundreds of thousands of American and Japanese soldiers. President Truman also helped found the United Nations in 1945, issued the Truman Doctrine in 1947 to contain Communism, and enacted the Marshall Plan to rebuild Western Europe. He also oversaw the Berlin Airlift in 1948 and the creation of NATO in 1949, an effort to provide security among western nations from the Soviet Union.