I don't know where you got that Texas retained the right to secede per the treaty. I do not believe that to be true. The only unusual thing granted was the ability to subdivide into more states, but not greater than 5, in order to gain more senators.Grundy1133 wrote:Texas would be allowed to secede per the treaty that was signed.
http://www.lsjunction.com/docs/annex.htm
http://thetexasrepublic.com/history-of- ... agreement/