Dionicio de la Garza was born circa 1767, the son of Francisco de la Garza Ballesteros and Juana Reyna.
He married Maria Monica Salinas on 2 Dec 1797.
In 1782, he lived at Junta de los Rios. The church census recorded that he was a youth, español, and 15 years old. His household included 11 people:
Francisco de la Garza Ballesteros, español, married, age 48.
Juana Reyna, española, married, age 41.
Juan Jose de la Garza, español, single, age 21.
Francisco Antonio de la Garza, español, a youth, age 18.
Cirilo de la Garza, español, a youth, age 17.
Dionicio de la Garza, español, a youth, age 15.
Juana Maria de la Garza, española, an unmarried girl, age 14.
Jose Celedonio de la Garza, español, a child, age 11.
Valentin de la Garza, español, a child, age 9.
Jose de los Santos de la Garza, español, a young child, age 6.
Maria Josefa de la Garza, española, a young child, age 3.