[T]hey said, Ill be a part of Mexico as long as you give us freedom and liberty."
Except they objected to the state religion (Catholicism) which they had to convert to in order to own land. And they insisted on their right to impose slavery on blacks.
In 1823, Mexico forbade the sale or purchase of slaves, and required that the children of slaves be freed when they reached age fourteen.[11] By 1825, however, a census of Austin's Colony showed 1,347 Anglo-Americans and 443 people of African descent, including a small number of free Negroes.[17] In 1827, the legislature of Coahuila y Tejas outlawed the introduction of additional slaves and granted freedom at birth to all children born to a slave.[11]
In 1829 Mexico abolished slavery, but it granted an exception until 1830 to Texas. That year Mexico made the importation of slaves illegal.[11] Anglo-American immigration to the province slowed at this point, with settlers angry about the changing rules. To circumvent the law, numerous Anglo-American colonists converted their slaves to indentured servants, but with life terms. Others simply called their slaves indentured servants without legally changing their status.[18] Slaveholders trying to enter Mexico would force their slaves to sign contracts claiming that the slaves owed money and would work to pay the debt. The low wages the slave would receive made repayment impossible, and the debt would be inherited, even though no slave would receive wages until age eighteen.[19] In 1832 the state passed legislation prohibiting worker contracts from lasting more than ten years.[20]
Basically they faked religion and revolted over slavery....