Seeking to identify unit -- Mech. 41st Btry, 5th A.A. Sec.

Dear Mr. Thickpenny,

Thank you for posting your request on History Hub!

"MECH" is an abbreviation for the rank of “Mechanic” that was used by the Coastal Artillery Corps (to include anti-aircraft units) and the Field Artillery Corps during World War I.  “41st Btry” refers to the 41st Anti-Aircraft Battery that received this designation in General Headquarters, A.E.F. General Order No. 204, Paragraph V, dated November 14, 1918. The battery was previously the Headquarters and Supply Company, 5th Anti-Aircraft Battalion.  “5th A.A. Sec.” is the 5th Anti-Aircraft Sector, the unit to which the battery was assigned. The 5th Anti-Aircraft Sector was also created under the same order and was previously designated as the 5th Anti-Aircraft Battalion.

We searched the National Archives Catalog and located two series titled Records of the 1st - 6th Anti-Aircraft Battalions, 1918 - 1918 and Records of the 1st - 19th Anti-Aircraft Sectors, 1917 - 1919 in the Records of the American Expeditionary Forces (World War I) (Record Group 120). We also located the record series Card File of Military Engagements of American Organizations, 1918 - 1918 in the Records of the War Department General and Special Staffs (Record Group 165) which includes a file for Anti-Aircraft. For access to and/or copies of these records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at Archives2reference@nara.gov.

Also, you may be interested in Archie in the A.E.F.: The Creation of the Antiaircraft Service of the United States Army, 1917-1918 by Charles Edward Kirkpatrick.

We hope this information is helpful. Best of luck with your research!