Naturalization Records can be obtained (Also, Declaration of Intent and Certificate of Arrival if available) if you provide an entry from “Illinois, Northern District Naturalization Index, 1840-1950”. The naturalization must have occurred in a Will County Court between 1840 and 1950.
The naturalization records of Will County are housed at a separate archive center. Entrance to the archives is by appointment only. Please allow up to two weeks for the record to be located.