Source:United States. World War I Military Muster Rolls and Rosters, 1916-1939

The FamilySearch collection title is "United States, Enlisted and Officer Muster Rolls and Rosters, 1916-1939", with a brief description as follows:

This military collection contains rosters of enlisted men that were prepared both monthly and bimonthly as well as rosters of officers. Rosters are most often arranged by type of unit and reporting unit. Records are originally housed at The National Archives at St. Louis.

Some of the Films have been indexed, but many have not. A full listing of available films (available online) appears at the catalog record.