Although Texas gained its independence in 1836, on September 11, 1842, Mexican forces under Brigadier General Adrian Woll captured the city of San Antonio. Texan forces under the command of Matthew Caldwell gathered at Salado Creek in order to repel the invading Mexican army. Colonel Caldwell's troops were succeeding in the battle of Saldo Creek on September 18th, but, in response to his call for volunteers, a group of 53 Fayette county volunteers under the command of Captain Nicholas M. Dawson were marching down from La Grange to join in the battle.
A short distance from the battle at Salado Creek, Dawson's group was intercepted by 500 mounted Mexican cavalry and pinned down. In the ensuing battle, 36 were killed, 15 taken prisoner and 2 escaped. A more detailed account of the battle can be read here.
In the winter of 1842, Texans set out to avenge the brutal Dawson Massace. Over 300 soldiers ignored official orders and marched south down the Rio Grande and attacked the border town of Ciudad Mier. In the battle, 250 Texans were captured and marched toward Mexico City. Within 6 weeks of captivity 181 escaped. 176 of them only to be recaptured a few days later while attempting to cross the harsh Mexican desert. These prisoners who were not executed were taken to the Perote Prison, the same prison where the 15 captives from the Dawson Massacre were being held.
In his outrage over the defiance of the Texans, Santa Anna ordered that 10% of the re-captured prisoners be put to death. A lottery was held to determine who would live and who would die. The escapees were forced to draw a bean from a pot in which had been placed 159 white beans and 17 black beans. Those who drew black beans were executed.
The remains lying beneath the monument on the bluff overlooking La Grange are of the 36 who died in the Dawson Massacre as well as those 15 who were executed in the black-bean incident by Santa Anna. You can read more about the black-bean death lottery here.
