This collection houses personal papers and memorabilia documenting Arnold W. MacKerer's service with the American Expeditionary Forces during World War I. Among these items are letters, MacKerer's pay record, materials from a class on gas warfare (including textbooks, notes, and an exam), excerpts from such newspapers as the Schweizer Zeitung and the Stars and Stripes, a map of France, a copy of the New Testament issued by the U.S. Army, two uniform patches, and two embossed uniform buttons.