HI! It looks like you got lucky today!I hope that it's the same person that you're looking for, but be aware that it's possible a common name.
My grandfather's name is Jesus Santillan born and raised in a small town in Zacatecas, Mexico.He left Mexico and came to the states not sure when, but ended up settling in Chicago.I'm first generation born in the US of A.He passed away in 1985, but is survived by his wife Dolores Santillan (yes, i was named after my grandmother), seven children, many grandchildren and great grandchildren. I have learned through death records that there were Santillan as far back as the late 1800's.So, the Santillan were in the states a very long time ago.
I have many relatives in Mexico City.In fact, one of my grandfather's sons is a doctor which still lives in Mexico.