The Contra Costa County Historical Society has the original naturalization documents for residents naturalized in Contra Costa County from 1850 to the 1980s. This is a treasure trove for genealogists. Photocopies of the naturalization documents can be purchased for $25. For those requiring a photocopy certified by the court as proof of citizenship, the charge is $50. Some personal identification will also be required for certified copies. Please send your requests to:


You can also click here to order by e-mail and pay through PayPal (payable to if you prefer.

The table of naturalization records that are in our archives are listed below. The names are organized alphabetically. This is only a partial list as the indexing of our naturalizations records is still in progress. If you do not see your relative listed, you should contact us to see if their records are in our archives as your ancestor's records may not have been entered yet in our database. Please be aware that in the early years, when the husband was granted citizenship, children were often included.

Due to the size of the database, we have split the index into several pages. Click below on the first letter of the surname you are researching to go to that section of the index.

A, B, C, D-E-F, G-H-I, J-K-L, M, N-O-P, Q-R, S, T-U-V-W-X-Y-Z

An historical service of the Contra Costa County Historical Society
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