How to Find Chicago Naturalization Records

Naturalization Process

Although there may be exceptions to this generalization, naturalization was usually a two-step process. First, a declaration of intention was filed, then, after a waiting period, a petition was filed to complete the process. John J. Newman's American Naturalization Processes and Procedures 1790-1985, published by the Indiana Historical Society, is a good resource for detailed information. It's also interesting to check period publications such as Charles Kallmeyer's 1917 How to Become a Citizen of the United States which is available on Google Books.

Record Availability

Due to Chicago Fire losses, Cook Count naturalization records are available from 1871 forward. They were created by five courts: Circuit, County, Criminal, Superior, and District. Records from the first four are held by the Cook County Circuit Court Archives. Records from the District Court are held by the National Archives at Chicago.

Information Included

The earliest Cook County naturalization records provide little, if any, genealogical information. However, some files include copies of declarations filed in other places and these records may incude helpful details. For example, a person might have filed a declaration in Maine, moved to Chicago, and provided a copy of the Maine declaration while completing the naturalization process in Cook County.

Records from 1904-late 1906 can include birth date and town, departure and arrival information, and occupation.

Records from October 1906 forward generally include birth dates and places for the applicant's wife and children and a physical description of the applicant.

For more information, please see the Cook County Circuit Court Archives Cook County Naturalization Records information sheet. It's available under the How to Order link on their Naturalization Declarations of Intention website.

The first step in finding a Cook Cook County naturalization record is to check an index.

Start by searching Illinois, Northern District Naturalization Index, 1840-1950 at FamilySearch.

If you don't find a match that way, use the Rootsweb Soundex Calculator to obtain the code for the surname you want to search, then browse the cards at the same site. They are arranged alphabetically by given name within each Soundex code group. Play the high-low number game to quickly find cards of interest.

Another option is to check the same Soundex cards at using their All U.S. Naturalization Record Indexes, 1791-1992 (Indexed in World Archives Project) database. It's searchable by name, birth year, immigration year, and state of residence.

Or, if you prefer microfilm, you can find the Soundex index at the Circuit Court Archives and at IRAD at NEIU. Indexes specific to the Circuit, County, Criminal, and Superior courts are also available on microfilm and these indexes (not the Soundex) are available at the Wilmette Family History Center or the Family History Library in Salt Lake City.

For later reords, check the Illinois, Northern District (Eastern Division), Naturalization Index, 1926-1979.

If you can find a match in the Soundex index, the petition number should lead you to all available records. If a declaration is available, a copy of it usually accompanies the petition.

If you can't find a match in the Soundex index, check the Cook County Clerk of the Circuit Court Naturalization Declarations of Intention index. It is possible that your ancestor began the naturalization process but didn't complete it.

Circuit, Criminal, County, Superior Courts

Naturalization records for the Circuit, Criminal, County, and Superior Courts, 1871-1929, can be obtained from the Circuit Court Archives.

If you're not able to visit in person, you can request a record by sending a copy of the Soundex card and $3.00 to the Cook County Circuit Court Archives, 50 W. Washington, Room 1113, Chicago, IL, 60602.

If you would like color images (expecially helpful for records from 1906 forward) and can't get to the Archives, both Kim ( and Steven ( make regular visits to the Circuit Court Archives and can provide digital copies of naturalization records.

District Court

Many District Court naturalization records are available online for free at FamilySearch in a database titled Illinois, Northern District Petitions for Naturalization, 1906-1991. Use the petition number from the Soundex index to choose the right record group, then browse to locate the matching record. The images are arranged by petition number but the volumes also include declarations which have their own numbers. Don't let that confuse you. An alternate strategy is to use the index in the front of the volume (where available) to identify a page number and then navigate directly to that page.

District Court naturalization records that aren't online at FamilySearch can obtained from the National Archives at Chicago in person or by mail with an online request.

In a Nutshell

Check the Soundex index online. Get Circuit, County, Criminal, and Superior court naturalization records from the Circuit Court Archives by mail for $3.00. Use petition numbers from the Soundex index to check FamilySearch Records for District Court naturalizations. If not available there, order them through the National Archives at Chicago's website. From the fall of 1906 forward, naturalization records have valuable genealogical information. Before that date, you will likely find little to no useful information BUT it's always worth getting a copy of the record to see what's there.


Where is the old Circuit Court Archives website?

The previous Circuit Court Archives website was rich with information. You can use the Wayback Machine to access it here. Just remember: while the old site can be useful for information that doesn't change, e.g., record descriptions, the current website should be consulted for the most recent information on hours and fees.

Which courts handled naturalization?

Early on, Cook County naturalization could take place in any one of five courts: Circuit Court, Superior Court, County Court, Criminal Court or the United States District Court. After 1929, all naturalization was done through the District Court. Fortunately, the Soundex index covers them all.

What information is found on Cook County naturalization records?

Please see the Circuit Court Archives Naturalization Record Searches information sheet to learn what information you'd expect to find on documents from various years.

Are any pre-Fire naturalization records available?

You are not likely to find naturalization records before 1871, but you may be able to find evidence that your ancestor naturalized.

Check the 1888, 1890, and/or 1892 Chicago Voter Registration records on Ancestry. They have a column for "Date of Papers" and "Court" which may tell you where and when your ancestor likely naturalized. If the naturalization took place outside Cook County, you will be able to pursue the documentation.

If evidence of an individual's citizenship was lost in the Chicago Fire, he may have gone to court to prove and document his status. Check with the Circuit Court Archives to see if any record of that might be available.

Check the 1870 census to see if an individual born outside of the United States was listed as a male citizen, 21 years of age or order. If so, he likely naturalized before the census was taken. The 1900, 1910, and 1920 censuses also asked about citizenship status.

Why did my ancestor naturalize in the Criminal Court?

Don't worry. It doesn't mean your ancestor was a criminal. But, it might mean that your ancestor was part of a pre-election push to naturalize immigrants so they could register to vote, especially if your ancestor naturalized in October. The Criminal Court was one that extended hours to accomodate those who wished to complete the process.1

1 See, for example, [no title], The Chicago Daily Tribune, 23 October 1872, p. 4, col. 2; digital image, Newspapers Publishers Extra ( : accessed 24 April 2018).

Was there naturalization fraud in Chicago?

Possibly. Check online newspapers to look for answers to this question. For example, a story from 1873 suggests that a saloon-keeper had a way of circumventing the legal naturalization process in order to help men become eligible to vote.1 Fraud was also a concern in 1892 when a plan to help keep the process honest was being discussed.2

1 "Fradulent Naturalization," Chicago Daily Herald, 3 November 1873, p. 2, col. 1; digital image, GenealogyBank ( : accessed 24 April 2017).
2 "Will Prevent Fraud. The Republicans Want an Honest Naturalization. Ask Democrats to Help," The Daily Inter Ocean (Chicago), 21 September 1892, p. 9, col. 1; digital image, GenealogyBank ( : accessed 24 April 2017).

Are naturalization records available on FamilySearch microfilm?

Yes. Many Cook County naturalization records can be found on FamilySearch films but they don't circulate anymore. So, unless you're in Salt Lake City, just get records held by the Circuit Court Archives by mail. The Wilmette Family History Center also has the films, but if you're in the Chicago area, why not just visit the Archives to take color photos of the originals?