CATHOLIC CHURCH. The Catholic Church has been a part of Texas history ever since Europeans first set foot on the land in 1528. In fact for the three centuries up to 1821-that is, during the Spanish Texas period-Hispanic Catholicism had a rarely challenged religious and civil monopoly among the European-origin settlers in what is now Texas. This in turn gave Hispanic Catholics complete control over Christianization efforts among the Indians. However, events after Mexican independence in 1821 soon left Catholics in a minority status in the land. But even then they always remained one of the largest single religious bodies in Texas, and Hispanics continued to be one of the largest ethnic groups among Texas Catholics.
Full article on the Texas State Historical Association's Handbook of Texas Online