 Complete the following phrase:  In the 18th century, the residents of Spanish Texas began to herd cattle on horseback to sell in Louisiana, both legally and illegally. Their horses were of jennet type which became the Spanish mustang. By the early 19th century, the Spanish Crown, and later, independent Mexico, offered empresario grants in what would later be Texas to non-citizens, such as settlers from the United States. In 1821, Stephen F. Austin led a group which became the first English-speaking Mexican citizens. Following 