Manifest Destiny was the belief that the United States was destined to expand from coast to coast. American settlers moved into Texas under Stephen Austin's colonization efforts, bringing slaves despite Mexico's abolition of slavery. This led to tensions and the Battle of the Alamo where Texan defenders were defeated by Mexican forces led by Santa Ana. Subsequently, Sam Houston led Texas to independence from Mexico and the Republic of Texas was created. The US then annexed Texas which triggered the Mexican-American War under President Polk, culminating in the Treaty of Guadalupe Hidalgo where Mexico ceded California and New Mexico to the US.