Harry S. Truman was the 33rd President of the United States, serving from 1945 to 1953. He was born in Lamar, Missouri in 1884 and served in the U.S. Army during World War I. After the war, he became a farmer and later a politician, serving as a judge and then as a U.S. Senator from Missouri. In 1944, he was chosen by President Franklin D. Roosevelt as his running mate, and after Roosevelt's death, Truman became President. During his presidency, Truman made several significant decisions, including dropping atomic bombs on Hiroshima and Nagasaki, Japan, and issuing the Truman Doctrine, which committed the U.S. to providing military and economic aid to countries threatened by communism. Truman also played a key role in the founding of the United Nations and the Marshall Plan, which helped rebuild Europe after World War II. Despite facing many challenges during his presidency, including the Korean War and the Cold War, Truman remained a popular figure with the American public and is remembered as a strong leader who made difficult decisions during a time of great crisis.