I don't like using Wikipedia but this might be a good start
It does say
In 2009, the Texas legislature authorized a court order relating to a person's sex change to be acceptable proof of identity for a marriage license.[69]
For geographical areas under the jurisdiction of the Texas Court of Appeals in San Antonio, the 1999 case Littleton v. Prange defined that, for purposes of determining the validity of a marriage, a person's sex is determined at birth and is not changed by surgery or drug therapy.[70] This ruling allowed a person born male who transitioned to female to marry a woman in that court's jurisdiction.[71][72] In February 2014, the Texas Court of Appeals in Corpus Christi held that state law had changed since Littleton and now recognized sex reassignment, so that parties to a lawsuit contesting whether or not a marriage was an invalid same-sex marriage or a valid different-sex marriage needed to have their dispute heard by a trial court
And just looking on Google some of the news coming out of Texas is scary.