Santa Anna and his forces surrounded the Alamo February 23, 1336. Both Texas and Mexico exchanged cannon shots for 13 days. Santa Anna did this so he could train soldiers and wait for all his troops. During this time William B. Travis wrote the most heroic document in history "Victory or Death"
After 13 days Santa Anna sent his troops in to kill every last Texan in the Alamo. The texans had around 200 soldiers. The Mexicans had around 4000. The fighting should have lasted only a couple of minutes, but instead asked 90 minutes until every last Texan was dead.
Despite Santa Anna's words on killing every last Texan. He left two alive. Susanna Dickenson and her child were given specific orders to go to the towns in Texas and tell people of the Alamo. This was meant to make them fear Mexico. Instead it made the Texans more angry and in the battle of San Jacinto was used as a battle cry "Remember the Alamo!"