Dear Mr. Snodderly,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located Records of Machine Gun Battalions, 1917 - 1920 in the Records of the American Expeditionary Forces (World War I) (Record Group 120) that include records of the 145th Machine Gun Battalion. Records of lower echelon units sometimes were incorporated into the files of the battalion. We also located Records of Divisions, 1917 - 1920 in Record Group 120 that includes the 40th Division and may include files of the 145th Machine Gun Battalion. For more information about these files, please contact the National Archives at College Park - Textual Reference (RDT2) via email at email@example.com.
We also located three additional records which have been digitized and may be viewed through the National Archives Catalog.
Copies of most of the monthly rosters from November 1912 - 1943 for Army units and morning reports for Army units from November 1, 1912 to 1959 are in the custody of the National Archives at St. Louis (RL-SL). For access to these records, please contact RL-SL via email at firstname.lastname@example.org.
Photographs of various U.S. Army activities and subjects during WWI are in the custody of the National Archives at College Park - Still Picture (RDSS). Please contact RDSS via email at email@example.com
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, RL-SL, and RDSS. We apologize for this inconvenience and appreciate your understanding and patience.
We suggest contacting the California State Military History and Museums Program. Some of the source they have online include California Militia and National Guard Unit Histories
Volume 3. 1917-1941 and California's Own: The History of the 40th Infantry Division. In addition, the California State Archives and the California State Library may have resources concerning the unit.
You also may wish to contact the US Center for Military History, which has made some World War I references available online. Plus, the US Army Heritage & Education Center and the National World War 1 Museum may be able to assist your research.
In addition, we searched online and located History of the Fortieth (Sunshine) Division: Containing a Brief History of All Units Under the Command of Major General Frederick S. Strong, 1917-1919. Lastly, we located a WorldCat entry for The complete roster of the Fortieth Division, Camp Kearney, California, November 15, 1917.
We hope this is helpful. Best of luck with your research!