He was born circa 1756. His father was Juan de las Casas, and his mother was Josefa de la Garza. His father owned Camargo 29 grant, Camargo 39 grant.
He married Maria Ignacia Vargas, daughter of Pedro de Vargas and Margarita Rendon on 20 Oct 1781 in Camargo. He was 25 years old. SAGA marriages book