After Stephen F. Austin was put in jail for so called rebellion by the Mexican government he was released. with about 6,000 soldiers, Santa Anna marched north. They were all looking forward to destroying the Rebels.
In 1836, much of Santa Anna's army got to San Antonio and attacked the rebels. The rebels were surrounded by the Mexican army. They were heavily outnumbered with their backs to the Alamo.
Texas Wins Its Independence
William Travis was commander (with James Bowie) and refused to surrender. He sent messengers to get reinforcements but none came. The rebels were in trouble.
To Annex Texas or Not
Santa Anna's army pounded the Alamo with cannon balls. Texans tried to fight with rifles but it didn't help. Every rebel was killed and it was an easy victory for the Mexicans.
Later on in the war, commander Sam Houston lead the Texans on a surprise attack on Santa Anna. The rebels surrounded the Mexicans and beat them handily. This resulted in Texas winning their independence and Mexico losing a lot of territory.
Texas was now independent so some Americans wanted Texas to become a state in the U.S. and some didn't want it annexed. Henry Clay (presidential candidate) thought annexation of Texas would lead to war with Mexico. His opponent James K. Polk beat Clay to become President because he believed in manifest destiny. Texas was then annexed to the U.S.