“The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.”
Under Article IV, Sec. 3, US Constitution, Congress has the power to admit new States into the Union. For a list of States and when admitted, see this wiki list. Note that the new States were “colonies” or “territories” – or as with Vermont and Texas, “independent...
