He was born circa 1777, and was baptized 30 Jul 1777 in Villanueva, Zacatecas. His father was Joaquin Casas, and his mother was Maria Zeferina Gertrudis Gallegos.
He married Isabel Maria Cabrera, daughter of Jose Maria Cabrera and Maria Josefa Figueroa on 14 Apr 1798 in Villagutierre de la Aguila, Zacatecas. He was 21 years old, and the bride was 15 years old.