Coahuila y Tejas
Jackson believed that Adams had bargained away rightfully American territory in the Adams–Onís Treaty, and he sought to expand the United States west. He continued Adams's policy of attempting to purchase the Mexican state of Coahuila y Tejas, which Mexico continued to rebuff. Upon gaining independence, Mexico had invited American settlers to that underdeveloped province, and 35,000 American settlers moved to the state between 1821 and 1835. Most of the settlers came from the Southern United States, and many of these settlers brought slaves with them. In 1830, fearing that the state was becoming a virtual extension of the United States, Mexico banned immigration into Coahuila y Tejas. Chafing under Mexican rule, the American settlers became increasingly dissatisfied.