There is a rumor going around that part of Colorado wants to secede from the rest of the state and become the 51st state. The last time a state was formed that way was back when Virginia seceded from the union. People in the western part of the state decided that they wanted to stay with the union, so they seceded from Virginia and became West Virginia.
There have been other occasions when it looked like that we would get a 51st state. There was talk about splitting Michigan into two states. The upper peninsula is completely separate from the rest of the state. As of this writing, Michigan is still one state. There was talk about making California into two states, but again, as of this writing, California is still one.
When I was in college there was a push to make the District of Columbia a state. It would be renamed New Columbia and would replace Rhode Island as the smallest state. Then I learned that it would require a change in the Constitution, so that never came to be.
Most recently, Puerto Rico, a commonwealth of the United States, turned down an opportunity to become the 51st state.
While it is true that no new states have been added since 1959, that doesn’t mean that there won’t be any more added.
Kent Syverson, Willmar