José Rafael Garza Sais

Possibly related to the Rafael Garza Sais, who received the Palitos Blancos land grant (13,472 acres in Jim Hogg County, Texas) in 1836 from the Mexican government, just prior to Texas independence.

http://www.vsalgs.org/stnemgenealogy/ugrants.html

http://books.google.by/books?id=8F1eGSL6_lwC&pg=PT2&lpg=PT2&dq=Rafa...

This potentially related earlier Garza Sais (according to Spanish custom still in use even today within Mexico, the paternal and maternal apellido would have been used at birth) had his cattle brand registered with US authorities on Oct. 25, 1848, toward the end of the US war with Mexico.

http://archives.lib.panam.edu/EAD/County/Starr-County-Marks-and-Bra...

If this is the case, likely, the Sais name (the maternal apellido) was retained as a last name for the family when registering as residents, the Garza name (the paternal apellido) becoming disused, resulting in a de facto name change. Since, if this supposed relationship is correct, this person was born within the United States, Garza was probably his middle name rather than part of the last name. (More research would be warranted.)