He was born circa 1756. His father was Gaspar Garcia, and his mother was Maria Gertrudis de la Barrera. His father owned Mier 1 grant.
He married Gertrudis Flores, daughter of Pedro Jose Flores and Gertrudis Canales on 9 May 1784 in Mier. He was 28 years old. Their padrino was Manuel [Jr.] Hinojosa, and their madrina was Maria de los Santos Garcia.
In 1782, he lived in Mier in household number 17. The church census recorded that he was single, español, and 26 years old. His household included 7 people:
Don Gaspar Garcia, married, español, age 52.
Doña Maria Guadalupe Flores, married, española, age 42.
Jose Antonio Garcia, single, español, age 26.
Jose Carlos Garcia, a youth, español, age 16.
Jose Tomas Garcia, a child, español, age 13.
Maria Francisca Garcia, a child, española, age 10.
Maria Ana Garcia, an unmarried girl, india, age 23.