Harry S. Truman (1884-1972)

"I realize the tragic significance of the atom bomb," President Harry Truman said in a radio address before the Japanese government finally surrendered, "[but we] have used it in order to shorten the agony of war, in order to save the lives of thousands and thousands of young Americans."

The Manhattan Project was so secretive that the Vice President of the United States didn't know about it. Within a few days of taking office, he had to be briefed on the entire project. The Trinity test was only 3 months away and in 4 months, he would have to pull the trigger!