They literally built two cities out of scrap, one of which is a converted aircraft carrier. This is despite the fact that unlike every other period in history, they'd be under constant attack by big yellow incredible Hulks and enormous monsters. The LW inspired people like Three Dog and others trapped in pessimism to rise above their circumstances.
Also, NCR would be extinct if not for the VD. They just got the help of the One Great Player Character of HistoryTM earlier.
I mentioned it would probably degenerate into a feudal state in my ambiguity essay and two years later, Arthur Maxson was revealed so called it!