The Texas Revolution had officially begun on October 2 and by the end of the month the Texians had initiated a siege of Béxar, home of the largest Mexican garrison in the province.
Bored with the inactivity, many of the Texian soldiers returned home; a smaller number of adventurers from the United States arrived to replace them.
On November 26, Texian scout Deaf Smith brought news of a Mexican pack train, accompanied by 50–100 soldiers, that was on its way to Bexar.
When the Texians examined the abandoned pack train they discovered that, instead of silver, the mules carried freshly cut grass to feed the Mexican Army horses.
Four Texians were injured, and historian Alwyn Barr states that three Mexican soldiers were killed, although Bowie and Burleson initially claimed the number was much higher.
[6] At 10:00 a.m. on November 26, Texian scout Erastus "Deaf" Smith rode into camp to report that a pack train of mules and horses and donkeys, accompanied by 50–100 Mexican soldiers, was within 5 miles (8.0 km) of Béxar.
[7][8] For several days, the Texians had heard rumors that the Mexican Army was expecting a shipment of silver and gold to pay the troops and purchase additional supplies.
Colonel Thomas Rusk led a group of 15 in an attack on the nearest Mexican cavalry; as those cavalrymen fled the Texian infantry was able to scramble to cover.
[13] In his book Texans in Revolt: the Battle for San Antonio, 1835, historian Alwyn Barr stated that only 3 Mexican soldiers had been killed and 14 wounded; most of the casualties were from the cavalry companies.
Instead, the mules had been carrying freshly cut grass to feed the Mexican horses trapped in Béxar; this prize gave the battle its name.
[12] Although the engagement, which historian J. R. Edmondson termed a "ludicrous affair", did not yield valuable plunder, it did serve to unite the Texian Army.
Although they had promised to leave the country, the men, including Samuel Maverick,[14] instead joined the Texian Army and provided information about the Mexican defenses and the low morale within the town.