What would the world look like if President Truman had not been killed by Griselio Torresola? I know there have been many a historian that have said that the assassination was Truman's own "fault," since he opened a window and looked out when Torresola and his accomplice were exchanging gunfire with the police, but that's not the point of this WI.
How would the Korean War have progressed with Truman's guiding hand? What would Puerto Rico be like without the infamous crackdown on anyone remotely pro-independence, which mars US and Puerto Rican relations to this day?