I am related to Cantu through marriage and am just starting to do research on that line of the family.
Angela (Maria De Los Angeles?) Cantu and Cesario Cantu were brother and sister. There probably more in the family but they are all I know of. They were born in Cadereyta, Nuevo Leon around the 1870's and came to the San Benito area in the very early 1900's.
Cesario was married to Juanita (last name unknown to me) and had Francisco, Isabel, Concepcion and another child. Francisco married Julia Rodriguez and had Francisco Jr., Gustavo, and Lupita (now a nun in San Antonio, Texas). Francisco is married to Belia Valdez, have 3 girls and live in San Benito, Texas. Gustavo (now deceased) married Rebecca Rodriguez, had three girls and a son Gustavo, Jr., living in San Benito also.
Angela Cantu married Rosario Montalvo and had Emilia (married Manuel De La Pena), Rosario Jr.(now deceased, married Ignacia Nerio)Jesus(deceased) married San Juanita (last named not known to me) and had Alfredo, Eduvina and Roberto, also around San Benito. Jose married Severina Garza and had Isaac and Emiliano (both now deceased)and Maria De Los Angeles, about whom I don't havr much information.
I imagine there are other Cantu's in the area. I have records of many Cantu's in Cadereyta, as well as Rios', Rodriguezes, Trevino's etc but I am missing the links which are the parents of Cesario and Angela to connect them to those Cantu's in Cadereyta and Monterrey, Cerralvo and surrounding towns in northern Mexico.
My own line is Martinez, traceable to Spanish soldier Francisco Martinez (born in 1803) in Nacogdoches, Texas in 1819.
If these Cantu's are of interest to you, I can provide other names or try to put you in touch with them. If you have any information you wish to share I would appreciate it very much. My e-mail is firstname.lastname@example.org