While researching my McElyea family, I came across some historical information and a book review on the Mier Expedition.
A short synopsis of the Texas Mier Expedition: A force of 750 Texas soldiers marched to the Rio Grande and captured Laredo (on the Mexico side at that time) in response to a Mexican attack on San Antonio in 1842. Gen. Somervell, the leader decided it was not prudent to stay in Mexico and he and more than half the men returned to Texas. The rest stayed on the border and moved downriver to Matamoras. Outside the town of Mier, the Texans surrendered to the Mexicans after a fierce battle. Seventeen prisoners were later executed in the so-called Black Bean episode. It was a lottery of death. Those who drew the black bean faced a firing squad. Those who drew a white bean were spared.
The list of participants included William J. McLeyea from Pennsylvania. He died of wounds December of 1842.
The following is the link to the list of participants: