What was the primary purpose of the Old Three Hundred families brought by Stephen F. Austin to Texas?

The primary purpose of the Old Three Hundred families brought by Stephen F. Austin to Texas was to settle and develop the region. Austin received a land grant from the Mexican government to encourage colonization in Texas, which was seen as a way to bolster the population and secure the land against potential threats. These families were tasked with farming and establishing a community, ultimately aiding in the cultivation of the land and the creation of a sustainable settlement in an area that was relatively undeveloped at the time. This initiative not only facilitated the growth of agriculture but also laid the foundation for Texas’s cultural and social development.

The other choices reflect different aspects of Texas’s history but do not capture the primary goal of the colonization effort. Establishing a new government and creating a military presence came later as the conflicts and dynamics with Mexico evolved. Promoting trade with Mexico was not the central focus of Austin's colonization plan; rather, the emphasis was predominantly on settlement and development to support the new communities and ensure their longevity.