I have been at a web site www.familysearch.org, and they have sacramental records, marriage dates, and death dates. In searching for Odocio Lolla (b. abt 1800 in TX or Mex), my great great great great great grandfather, I've only been able to find him on US census records as far back as 1850.
My suggestion would be to see where Theodocio was baptized, find out if the church has records, and do a sacramental records request. Also, see if Mexico has vital statistics and census records.
I have yet to start really truly searching for Odocio and where he came from. All I know so far is that he worked for the King Ranch people on their steam boats. Census records in Louisiana, where he may have traveled to, have yielded nothing, so I think I'll have to start in Texas and then work my way back to Mexico.
Best of luck to you Kenny. You're already on the right path.