In the collection are letters written by Hector C. Henderson, serving as a private (later promoted to corporal) in the 1st Wellington Company, New Zealand Expeditionary Force to his American pen pal, Mae Josephine Gillette in Winsted, Connecticut. Writing from New Zealand, England, France, and Germany, Hector filled 41 letters (237 pages) and 2 postcards with his observations and experiences of World War I.

The first letter, sent from New Zealand in 1915, is written in shorthand (Gregg method). They probably became acquainted through a shorthand pen-pal club. A 1916 letter notes that the military does not allow the sending of shorthand letters. The rest of the correspondence, written in pen or pencil on a variety of papers, is in ordinary cursive script. In November 1918, he mentions his engagement to an English girl, and the correspondence ends in 1919 at the end of the war. Henderson's letters must have been kept by Mae, who married Benjamin J. Wood of Millinocket, Maine.

Also in the collection are various photographs. Some show Mae at various ages, her parents, and other family members; one shows Hector Henderson.