I remember the day that Franklin Roosevelt died. It was in the spring of 1945 and I was only six years old at the time. I heard the announcement on the car radio as my mother and I were leaving my grandmother's house. Thanks to my father and grandfather I was very politically aware even at that early age. After our frequent Sunday dinners together, they would sit and argue politics and I would sit and listen. I have been a political junky ever since.
So now Harry Truman was president. At the time, he was much vilified and got little respect even within his own party. He rose to the rank of Colonel in the US Army and upon leaving the army after the First World War ran for the senate from Missouri. With the support of the infamous Pendergast machine he won. Roosevelt asked him to be his running mate because Roosevelt thought he could be controlled and would not create problems. Truman got so little respect that he was never told about the Manhattan project or the atomic bomb. He found out only after he had become president.
When Truman became president he apparently separated himself from his old political cronies and tried to do an honest job. One month into his presidency WW I ended. He took no credit for himself. But that did leave the war in the Pacific to be dealt with. He was aware that Japan was arming it's citizens to protect the homeland for the emperor. His military experience told him the fight would be long and bitter. A great many lives would be lost on both sides. As soon he had two A-bombs he made the decision, though they were untested, to drop one on Hiroshima and one on Nagasaki. Japan sued for peace. The war was over.
Although he tended to be a bit irascible, he wanted to known as a good president. Hence his two most famous quotes. "The buck stops here", and "If you can't stand the heat, stay out of the kitchen". He did not "lead from behind", blame everyone but himself when things went awry, or throw people under the bus to save his own sorry behind. Why don't we have presidents like that any more?