The Lionel Cherry Gilmour World War I Collection is comprised of a small photograph album, loose photographs, a prisoner-of-war diary, and assorted research documents pertaining to the World War I service and prisoner-of-war (POW) experience of Lieutenant Lionel Cherry Gilmour (1891-1973) of the Royal Air Force (RAF) and its predecessor, the Royal Flying Corps (RFC). The collections has been arranged into two series: personal materials of Lionel Cherry Gilmour and research materials.

Series I, Personal Materials, includes Gilmour's personal handwritten diary describing how he was shot down on July 31, 1918. It continues describing his first few weeks as a POW at various German camps, including Karlsruhe, Germany. Additional materials include a small black leather photograph album, which holds approximately 40 photographs depicting military personnel in both posed and casual settings; military buildings and the interior of a church; and military aircraft. Many of the photographs have faded and are difficult to see clearly. Pages typically have one to four photographs that have been affixed with photo corners and/or glue. However, many photographs are loose or have been removed/fallen out. Images often include very brief captions. People are generally identified only by rank and last name (ex. "Lt. McDonald").

Two photographic postcards were found on the top of the album. One features Wantage Hall in Reading, England, where Gilmour was in training, and the other depicts Lionel Cherry Gilmour in his training uniform. Both have handwritten captions on the reverse that provide contextual information, including date, location, and names. The photograph album also has a front pocket, which held a small envelope with one photograph. The photograph has faded but a man with a motorcycle is vaguely discernible. On the back of the photograph is "Lieut. Botterell and motorcycle." The front pocket also included two additional loose photographs, one which depicts an Avro crash and one which depicts a hand-colored image of a pilot, likely Gilmour, in the cockpit of an airplane.

Additional materials include 36 loose photographs and photographic postcards that were originally housed within three different envelopes. All are black-and-white and most often include captions on reverse, with some having contextual information on the front of the image.

• Envelope 1: "Kamstigal bei Pillau" - a postcard and seven photographic postcards depicting a waterfront scene and group portraits of military personnel in uniform.
• Envelope 2: "Karlsruhe photographs, Fritz Albrecht, photographer - twelve photographic postcards depicting captured military personnel in both casual and posed settings.
• Envelope 3: Sixteen photographs and photographic postcards depicting military personnel, aircraft, and one scenic image. One image depicts two bare-chested men, likely POWs, with arms upright standing before a soldier with a gun. These images were likely removed from Gilmour's photograph album.