Dear Ms. Schildroth,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the series Indexes to the Carded Records of Soldiers Who Served in Volunteer Organizations During the Civil War, 1899 - 1927 in the Records of the Adjutant General's Office, 1762 - 1917 (Record Group 94) that includes the index cards Fitzgerald, James J - Unit: 23rd Infantry, Company: I - Enlistment Rank: 1 Lt, Discharge Rank: Capt and Coffey, Charles - Unit: 23rd Infantry, Company: H - Enlistment Rank: Capt, Discharge Rank: Capt. The index cards indicate that there should be Compiled Military Service Records (CMSRs) for these two officers in the records series Carded Records Showing Military Service of Soldiers Who Fought in Volunteer Organizations During the American Civil War in the Records of the Adjutant General's Office, 1762 - 1917 (Record Group 94).
Most of the service records in this series have been made available via microfilm and through digitization of the microfilm. Unfortunately, the records for Illinois Volunteers have not been microfilmed or digitized. To order copies of service records (except for OMPFs) not already available in the National Archives Catalog, please fill out a NATF Form 86 for the service records and mail the completed form to the address listed on the form. For more information see Requesting Copies of Older (pre-WWI) Military Service Records. There is a reproduction fee for this service.
The majority of Civil War pension files in the Records of the Department of Veterans Affairs (Record Group 15) are in the custody of the National Archives at Washington, DC - Textual Reference (RDT1). There are also 3 record series (XC files) in Record Group 15 at the National Archives at St. Louis (RL-SL) that include claims files relating to Civil War Veterans. These records were transferred to the National Archives in 1952 and 1955 from the VA. Please email both RDT1 at firstname.lastname@example.org and RL-SL at email@example.com with full details about the files you are seeking, and they can advise you as to which facility holds the records and how to request copies.
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 RDT1 and RL-SL. Also, please note that NARA has suspended reproduction and digitization services until further notice due to COVID-19. Orders will not be serviced until operations can resume safely. NARA has also temporarily suspended the option for placing online orders using eservices.archives.gov. Once operations resume, document reproduction requests will be filled in the order in which they were received. We apologize for any inconvenience.
We hope this is helpful. Best of luck with your research!