I have read it was mexican policy at the time to invite immigration to its northern regions because the Mexico could not control the Apaches. They figured gringos could and finally make productive use of the land.
Americans who took them up on it did so in part because Mexico had a constitution that was more or less similar to the one they were used to.
Inviting Anglo Americans to settle in sparely populated Texas began under Spain's rule and continued under Mexican rule.
The Texas Declaration of Independence goes into much detail why Anglo Texans could no longer tolerate the abusive Mexican government. Texas Anglos [who were mostly Protestant] were also rebelling against the Mexican supremacy of the Catholic Church. In our current day the Left's cultural marxist social agenda has become the new religion of the federal government who has also imposed the state's new cultural marxist religion on us at the point of bayonets.
Here is a quote... go to link for the entire document.
" The Unanimous Declaration of Independence made by the Delegates of the People of Texas
in General Convention at the town of Washington on the 2nd day of March 1836.
When a government has ceased to protect the lives, liberty and property of the people, from whom its legitimate powers are derived, and for the advancement of whose happiness it was instituted, and so far from being a guarantee for the enjoyment of those inestimable and inalienable rights, becomes an instrument in the hands of evil rulers for their oppression.
When the Federal Republican Constitution of their country, which they have sworn to support, no longer has a substantial existence, and the whole nature of their government has been forcibly changed, without their consent, from a restricted federative republic, composed of sovereign states, to a consolidated central military despotism, in which every interest is disregarded but that of the army and the priesthood, both the eternal enemies of civil liberty, the everready minions of power, and the usual instruments of tyrants.
When, long after the spirit of the constitution has departed, moderation is at length so far lost by those in power, that even the semblance of freedom is removed, and the forms themselves of the constitution discontinued, and so far from their petitions and remonstrances being regarded, the agents who bear them are thrown into dungeons, and mercenary armies sent forth to force a new government upon them at the point of the bayonet.
When, in consequence of such acts of malfeasance and abdication on the part of the government, anarchy prevails, and civil society is dissolved into its original elements. In such a crisis, the first law of nature, the right of self-preservation, the inherent and inalienable rights of the people to appeal to first principles, and take their political affairs into their own hands in extreme cases, enjoins it as a right towards themselves, and a sacred obligation to their posterity, to abolish such government, and create another in its stead, calculated to rescue them from impending dangers, and to secure their future welfare and happiness.
Nations, as well as individuals, are amenable for their acts to the public opinion of mankind. A statement of a part of our grievances is therefore submitted to an impartial world, in justification of the hazardous but unavoidable step now taken, of severing our political connection with the Mexican people, and assuming an independent attitude among the nations of the earth.
The Mexican government, by its colonization laws, invited and induced the Anglo-American population of Texas to colonize its wilderness under the pledged faith of a written constitution, that they should continue to enjoy that constitutional liberty and republican government to which they had been habituated in the land of their birth, the United States of America.
In this expectation they have been cruelly disappointed, inasmuch as the Mexican nation has acquiesced in the late changes made in the government by General Antonio Lopez de Santa Anna, who having overturned the constitution of his country, now offers us the cruel alternative, either to abandon our homes, acquired by so many privations, or submit to the most intolerable of all tyranny, the combined despotism of the sword and the priesthood. "
more at link
https://www.tsl.texas.gov/treasures/republic/declaration.html