Silvestre De León, one of the founders of De León's colony and the city of Guadalupe Victoria, was born in 1802 in Texas, the second son of Martín and Patricia De León. He was a chief merchant in the colony and one of the ten principal citizens referred to by the name of the town's main street, Calle de los Diez Amigos. He served as third alcalde and with his brother-in-law Plácido Benavides was a captain of the militia defense against hostile Karankawas, Tonkawas, and Comanches. The first Christian births recorded in the colony were those of the children of Silvestre and Rosalie de la Garza De León. The couple settled on a league of land on the Guadalupe River near the site of present Nursery, Texas, and received their grant from the Mexican government on April 2, 1833.
Silvestre joined his brother Fernando De León, brothers-in-law Plácido Benavides and José M. J. Carbajal, and John J. Linn in gathering local support for the Texas revolt against Antonio López de Santa Anna. De León contributed provisions, livestock, and military equipment to the Texas army and joined Benavides's company of thirty Mexican rancheros who participated in the siege of Bexar in December 1835. He also was elected with John J. Linn and Juan Antonio Padilla to the Consultation of 1835 but probably never arrived at either Columbia or San Felipe because of his service in the Texas army. Upon the occupation of Guadalupe Victoria by Gen. José de Urrea, De León was arrested by the Mexican army as a traitor; he was released after the Texan victory at San Jacinto but then fell victim to the severe prejudice directed against all Texans of Mexican descent. Forced to flee with the De León, Carbajal, and Benavides families to Louisiana, he lost his land, livestock, and most possessions to fortune hunters, though he later resettled in Victoria County. While returning from selling horses, mules, and cattle in Louisiana he was ambushed, murdered, and robbed in 1842 under still mysterious circumstances.