What was the primary reason Mexico repealed the ban on slavery?

The primary reason Mexico repealed the ban on slavery was to encourage American immigrants to settle in Texas. During the 1820s, Mexico sought to attract settlers to promote economic development in its sparsely populated northern territories. By reversing the slavery ban, Mexico aimed to make its land more appealing to American immigrants, many of whom were from the southern United States where slavery was a fundamental part of the agrarian economy. These American settlers were often familiar with plantation agriculture, and the presence of slavery would facilitate the growth of crops like cotton, which was vital for the economy.

While the other options relate to various aspects of labor and defense within the region, they do not encapsulate the specific motivations behind the repeal of the slavery ban as effectively as the desire to attract American immigrants. Strengthening the military and maintaining control of labor needs were important considerations but were secondary to the objective of increasing settlement and economic activity.