That's interesting. We are still united, but I think most people would look on the US as a single entity, not co-operating states anymore. States have lost most of their sovereignty. But then again, at the time we came up with the name, it was more fitting.
I wondered if North Korea had a similar history, but it appears they were always a communist dictatorship (since 1949, just after Korea split). [http://en.wikipedia.org/wiki/History_of_North_Korea]