For the most part the states didn't enter anything freely or voluntarily. They asked to be admitted. They gained statehood only with the approval of the majority of the other states.
Not Texas, which petitioned for admission but which action was never acted upon by the US congress. Then, with the creation of the Confederacy, and against the best counsel of some of the Texian founders and statesmen, Texas instead *jined up* with the Confederacy, and was thereafter occupied by Unionist forces as conquered enemy territory.
Texas was afterward *readmitted* to the Union, though in fact had never previously been admitted as constitutionally prescribed. So if I'm to keep the pledge I swore to support and defend the Constitution of the United States, Texas isn't really a state.
-archy-/-
So you're saying that Texas wasn't a state prior to the Civil War?