Birth, death, or marriage information that occurred abroad
to U.S. citizens may be obtained from:
The U.S. Department of State
1111 19th Street NW Suite 510
Washington DC 20524
Phone: 202-647-0518 or 202-955-0307

Authenticating birth or death certificates (Apostille)
Texas Secretary of State
There are several addresses for this -
please click on link to see which one is more appropriate for your needs