Dear Mr. Ray,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located these series of the FBI Central Records: the Classification 100 (Domestic Security) Case Files, 1939 - 1984 from the Chicago Field Office; the Classification 100 (Domestic Security) Headquarters Case Files, 1939 - 1984; the Classification 157 (Civil Unrest) Headquarters Case Files, 1/1/1957 - 12/31/1978 and the Classification 157 (Civil Unrest) Case Files, 1957 - 1978 from the Chicago Field Office in the Records of the Federal Bureau of Investigation (Record Group 65) that may include the information you seek. For more information about these series, please contact the National Archives at College Park - Textual Reference (RDT2) at firstname.lastname@example.org.
More information regarding these FBI record classification numbers and related series at the National Archives is located on the Record Classification Number 100 (Domestic Security) and Record Classification Number 157 (Civil Unrest) webpages. An explanation about the Central Records classification filing system is available on NARA’s website at Central Records of the Federal Bureau of Investigation (RG 65).
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
The Federal Bureau of Investigation has an electronic vault that includes digital copies of investigation files concerning espionage, famous persons, gangsters, unusual phenomenon, violent crimes, and those of historical interest. To view these files, please search the FBI Vault website.
We suggest you contact the Chicago History Museum Abakanowicz Research Center via email at email@example.com regarding their Red Squad Collection. We also suggest you contact the Archives of Michigan at Archives@Michigan.gov as well as the Michigan State Police, Records Resource Section, P.O. Box 30634, Lansing, Michigan 48909 or email MSPRecords@Michigan.gov for information about the Michigan State Police activity with the Chicago Red Squad.
We hope this is helpful. Best of luck with your research!
Many thanks for your reply, Zachary - I look forward to beginning this puzzle!