Obviously Normandy wasn't done by just the U.S. But stop and think about all the major operations the U.S. military was doing simultaneously in 3 different parts of the world. It's nothing short of amazing! I don't know if any other country has ever done anything like that.
The US entering WWI also spelled the end of the war. Now we’re giving away air force bases and entire fleets of jet fighters. (And I don’t even have ONE jet fighter!)