The Texas State Genealogical Society is offering a First Families Certificate to individuals who are direct or collateral descendants of settlers who resided in Texas prior to 2-19-1846. Membership in TSGS and TX residency are not required, but lineage must be proven by primary documents.
For an application, send a SASE with .55 postage to Wanda L. Donaldson, 3219 Meadow Oaks Dr., Temple, Tx 76502-1752
For this you need census data, birth certificates, naturalization papers, land records, anything governmental that will put your ancestor here. Death Certificates are OK, but since a relative gave the info, some of it may not be reliable.