Can you make a copy of the document listing his units and post it here? The reason I ask is because there may have been multiple A companies in the Signal Corps during the war, and I was wondering if there is anything on the record indicating a higher level of organization such as a battalion number.
Dear Mr. Rouleau,
Thank you for posting your request on History Hub!
During World War I, the US Army Signal Corps was made up of multiple signal battalions, each of which had an A Company. “A” Corps is not a term that was used to designate any units. We searched the National Archives Catalog and located Records of Divisions, ca. 1918 - 1942 and Records of Field Signal Battalions, 1917 - 1922 in the Records of the American Expeditionary Forces (World War I) (Record Group 120) that include records of signal units that were deployed to France. However without a battalion number, we are unable to locate your grandfather’s unit records.
Please post copies of the documents you mention to History Hub so that we may be able to help you determine what unit he served in. Alternatively, you may email them to the National Archives at St. Louis (RL-SL) at email@example.com or the National Archives as College Park - Textual Reference (RDT2) at firstname.lastname@example.org for assistance in interpreting the unit designation.
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 RL-SL & RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this information is helpful.