Texas Naturalization and Citizenship
Naturalization records have generally been filed with the clerk of the district court in each county. You can obtain copies of the declarations, affidavits, orders of admission, and other documents by contacting the clerk's office. The Family History Library has microfilm copies of some county records. For example, from Harris County the library has naturalization records from 1891 to 1906 and an index from 1855 to 1906.
For naturalization records after September 1906, contact the National Archives—Fort Worth Branch or the local office of the United States Citizenship and Immigration Services (formerly INS).