Family Tree Friday: Using military unit and operational records–World War I

A recent post in the “NARA Coast to Coast” blog here on NARAtions (see Pay Day for Some World War I Military Personnel Records from September 27, 2010) highlighted problems in researching 20th century military service that resulted from the July 12, 1973 fire at the Military Personnel Record Center in St. Louis, Missouri.  In addition to the Personnel Center’s efforts to recreate lost service information with auxiliary records, another useful way to supplement your research on U.S. Army service in the 20th century (especially for veterans of World War I through the Korean War) is to look at the military unit and operational records that are available at the National Archives at College Park, Maryland.  As long as you know a veteran’s regiment and the combat division it was attached to, it may be possible to find details about the activities of that unit during a particular war or theater of operations (which in turn will give you some idea what your veteran did during his service).  For the rest of this post we’ll focus on a few available sources for World War I service.

Most records relating to U.S. military participation in World War I are part of Record Group 120, Records of the American Expeditionary Forces (World War I).  The principal series to look at in this record group is Entry 1241, “Records of Combat Divisions” (ARC ID 301641)which includes information about the 1st-20th, 26th-42d, and 76th-103d U.S. Army Divisions, from 1917-19.  The records are arranged numerically by combat division and attached miscellaneous units, with divisional records organized first, followed by brigade records and then individual units (including infantry regiments and such tactical support units as machine gun battalions, field artillery brigades and regiments, trench mortar batteries, supply trains, ambulance companies, field hospitals, signal battalions, and engineer regiments).  The combat files under each hierarchy (division, brigade, and regiment) typically consist of unit histories, station lists, operations reports, messages, field orders, correspondence, general orders, special orders, bulletins, and memorandums.  A related series of records also includes Entry 271, “Journals of Operations” (ARC ID 649851), which consists of journals submitted to Operations Branch (G-3) of the AEF by various U.S. armies, corps, and divisions (as well as some French Army units). The journals include summaries of intelligence, memorandums on the placement of units in the field, and weekly and daily reports of combat operations with the Allied armies as well as the independent AEF offensives at St. Mihiel and the Meuse-Argonne.

As you contemplate Veteran’s Day this year (held, of course, on the anniversary of Armistice Day, which ended World War I), consider these supplementary records that collectively document the service of each combat division in the AEF during its participation in “The War to End All Wars.”

4 thoughts on “Family Tree Friday: Using military unit and operational records–World War I

  1. looking for grandfathers (philip pollerano) unit of ww 1, have this information ; Co G 16th —— 7 Division (june 5th, 1918)
    looks like Camp Kearny, California. Hope you can find any information on this unit and deployment unit or unit actions. thx Gy

    1. Hi Ralph,

      The National Archives has the unit records for all combat divisions that participated in the American Expeditionary Forces during World War I. These records are held at our research facility in College Park, Maryland. Your best option to help identify the unit from the information you already have would be to contact the military reference archivists who are in charge of the AEF records. You can contact them directly at Good luck with your research!


  2. I have a copy of my grandfather’s Draft Registration (Fred Morgan Brown); the registrar’s report is dated “June 5” probably 1917 – Los Angeles – and I believe he also was a Camp Kearny (from info on photos). Because my great-grandmother died while my grandfather was overseas (France), I would like to know the date that he left to go overseas.

    1. Hi Anita,

      The National Archives at St. Louis holds Official Military Personnel Files (OMPF) for veterans who separated from the service prior to 1952. You can find more information about requesting these archival records on our website:

      You can also contact them by phone at 314-801-0800, via email:, or visit their website for more information:

      Best of luck with your research,

Leave a Reply

Your email address will not be published. Required fields are marked *