I am available for document retrieval at the National Archives Chicago branch. I can obtain copies of all/any documents you request.
One of the largest uses of this archive, is naturalization records. The Chicago branch of the National Archives, currently maintains naturalization records for the following states: Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin. You can find a detailed time-table of dates and places here:
Applicable copy fees also apply. Most copies through NARA are $0.80/page.