Truman did some very good things: he took the measure of Stalin immediately and did not have the trust in “Uncle Joe” that FDR had cultivated. Second, he did not hesitate to end WW2 by dropping the atomic bombs - it had to be done and he said he had the best sleep of any night the evening he ordered it done. Third, he overrode his entire Cabinet by his one vote to resupply Berlin in the Berlin Airlift. Fourth, he integrated the armed forces - you can’t ask a man to die for his country and then tell him that he has to be in a separate unit bc of his race.
Fifth: He recognized the State of Israel.