Question

What did the mexican government do in the 1820s in order to "civilize" the region of mexico we now know as texas?

Answer 1

The answer to your question is:

The mexican government "Encouraged" the Americans to populate the region of Mexico we now know as Texas.

Answer 2

The answer to the question above is they allowed American immigrants to populate Texas.
Under the Empresario System, the Mexican (in order to civilize Texas in 1820s, after they achieved their independence) government allowed American immigrants to settle and populate on Texas.