The Goliad Massacre started on March, 19 1836. Santa Anna decided to take out all the Texians at Goliad for revenge. Mexican Army had 1000 soldiers while Texian Army only had 400!
We WILL take you out.
James Fanin the leader of the Texian Army made a big mistake by staying back while the Mexican Army was traveling to Goliad to fight. At the last minute Fanin decides to actually evacuate with the rest of the 400 men.
Soon the Mexican Army surprised the Texian Army while trying to escape. The fight began without notice and the Texian Army decided to surrender. The next day all of the Army that surrendered were executed. Santa Anna believed the he should always kill Pirates or "Filibusters" so he killed them all and didn't keep them as prisoners.