What it says on the tin.
The American impresarios/promoters of settlement in Texas happen to be antislavery and do their settler recruiting first and foremost from people not expecting to have slaves. The people most invested in and influential in the settlements and the ones winning the land grants Mexico recognizes fall into this category.
Their influence is decisive enough that slave property never becomes secure in customary local law and usage (and of course it was never legal under Mexican federal law).
How do things go from the 1820s through 1860s in Texas in this case?
The American impresarios/promoters of settlement in Texas happen to be antislavery and do their settler recruiting first and foremost from people not expecting to have slaves. The people most invested in and influential in the settlements and the ones winning the land grants Mexico recognizes fall into this category.
Their influence is decisive enough that slave property never becomes secure in customary local law and usage (and of course it was never legal under Mexican federal law).
How do things go from the 1820s through 1860s in Texas in this case?