In the 1820s and ’30s, Mexico struggled with ongoing political upheavals as it fought for independence from Spain. During that time, it also fought to keep control of Texas. Many Americans were unhappy with the way in which Mexican rulers like Santa Anna were dealing with the citizens of Texas, and they decided that Texas should belong to the United States instead. Men like Sam Houston, Jim Bowie, and Davy Crockett worked hard to free Texas from Mexican rule, bringing the fight to an old mission-fort called the Alamo.