Also in that link is what I was referring to:
Texas could split into five states.
Contrary to popular belief, Texas has no more right to secede than any other state. But its 1845 annexation agreement does permit its division into as many as five states without federal approval. “The joke is that if there were five states, then who would get the Alamo?” Brinkman said. “Or would it be a pie ridge radiating out from that site?” No serious attempt at splitting up Texas has been made since Reconstruction, and the idea has never been tested in the courts. Nonetheless, the state’s hypothetical partition still gets kicked around occasionally. In 1969, for example, a state senator proposed a 51st state within Texas that would be open to parimutuel betting, while in 1991 a state representative introduced a bill to turn the panhandle into a state called “Old Texas.”