It's kinda amazing that I've made it this far in my life without ever questioning what Columbia meant. There's a river, a university, a space shuttle, towns galore other than the one and only Washington, District of Columbia. How odd that I've never thought to even question the meaning. How intellectually incurious of me! Google to the rescue!
Imagine my surprise to realize the etymology of the word. If you didn't already know (Cliff didn't!), Columbia derives from Christopher Columbus. As in this is the land that Christopher Columbus discovered. Well, not really, but we did believe that for such a very long time.
I'm not sure why, but dictionaries specify that the United States (rather than the whole New World) is Columbia. Other countries in the Americas tend to consider the United States as arrogant to refer to ourselves as Americans. But I don't think I've ever heard anyone express negative feelings for Colombia on the same grounds. Both Columbia and Colombia surely have the same source.
Better to learn a thing late rather than never, hmm?