During this period, California and Texas were flooded by Anglo American businessmen. These migrants were welcomed into the region, and intermarriage between U.S. men and Mexican women was common practice, as it was a way to secure business loyalties through familial bonds. Yet the continual flood of Americans into the Northern territories grew into an ever-larger issue for the Mexican government. In 1835, less than 14 years after Mexico's independence from Spain, American ranchers in Tejas revolted against Mexico and declared themselves the Republic of Texas. Mexico's President Santa Anna led an army to put down the "filibusteros", but after initial victories at The Alamo and Goliad, Santa Anna's army surrendered defeat on April 21, 1836. The Republic of Texas was never recognized as a sovereign state by the government of Mexico, which refused to recognize the treaties signed by Santa Anna, as he was a hostage when he signed them. In the new Republic of Texas, Tejanos faced severe educational and economic discrimination. Meanwhile, Mexico struggled to maintain its hold on political stability following the rebellion in Texas. In fact, the nation went through eighteen Presidential administrations from 1836 to 1845.