Two weeks after the defeat at the Alamo, 350 Texans surrendered to Mexican forces near Goliad with the understanding that they would be treated as prisoners of war. Instead, Santa Anna ordered the men shot.
After the defeats at the Alamo and Goliad, volunteers from the American South flocked to Sam Houston's banner. On April 21, 1836, his army of less than 800 men surprised and utterly defeated Santa Anna's army as it camped out on the San Jacinto River, east of present-day Houston. The next day, Houston's army captured Santa Anna himself and forced him to sign a treaty granting Texas its independence, a treaty that was never ratified by the Mexican government because it was acquired under duress.
For most Mexicans in Texas, defeat meant that they would be relegated to second-class social, political, and economic status. The new Texas constitution denied citizenship and property rights to those who failed to support the revolution. All persons of Hispanic ancestry were considered in the "denial" category unless they could prove otherwise. Consequently, many Mexican landowners fled the region.
The following letter reports the news that the Texans had taken Santa Anna prisoner at the Battle of San Jacinto.
We one day have news that St. Anna has been taken by the Texans and next day contradicted, but I believe the general opinion seems to be that he is really a prisoner. We have not had any mail from New York for nearly a week as its passage has been wholly obstructed by the rising of the Indians in Alabama and Georgia. The last news we had from Columbus Geo[rgia] was that from 4 to 5000 people had abandoned their homes and fled to that town for protection.... The authorities compel every person who is able to carry a gun to turn out twice in each day to drill and make them take turns standing guard. All is alarm and confusion in all the frontier settlements....
Since the foregoing was written Genl. Houston has arrived in this city, the Commander in Chief of the Texan army and confirmed the news of the capture of Santa Anna & entire destruction of the Mexicans. They have 2000 prisons among which are 40 officers all the principal men in Mexico. Gen. Houston has come here for Surgical aid being badly wounded in the battle of 21st of April which resulted in the capture of Santa Anna and his entire army. The Texians were 650...and the force under St. Anna amounted to 1700 and subsequently another division descended.... The whole Mexican force that invaded Texas amounted to 7000 and the whole force Genl. Houston had in the field has not at any one time amounted to more than 700 or 800 men, and has entirely destroyed this immense army. Who will say after this anything is impossible with Americans.