Harold Hanne Elarth (b. 1885) was a U. S. Army officer who served in the Philippine Constabulary and rose to the rank of Lt. Col. The collection contains research for Elarth's book on the Philippine Constabulary, Philippine Constabulary Officers Association history, a diary, letterpress copybooks, a Philippine Constabulary manual, photographs, and correspondence.
Joseph V. Thebaud (1888 - ) served in the Philippine Constabulary in 1912, resigned in 1915, and later served as an officer in the U.S. Army. The collection (1912-1916) contains diaries covering Thebaud's experience in the Constabulary, manuscript maps, and photographs.