Another great tool when researching South Texas and Northern Mexico Genealogy is PARES (Portal de Archivos Espanoles).
Don’t forget to run your ancestor names in their archives search since it contains numerous collections pertaining to mexico and all of Spaniard territories before the 1800′s I found a document as old as 1695 which pertained to one of my ancestors dying intestate and how the family was dividing his estate. The Spanish will be sometimes hard to read but we have to adapt.
This archives contain documents all the way from brawls due to love affairs up to Spaniard officer files. Fortunately in my family tree I have quite a bunch of Spaniard officers. I’ll be posting some findings in future posts.