Smith wrote this diary as a young lieutenant with the American Expeditionary Forces in England and France during World War I. The diary, which begins with Smith's departure from New York City aboard a troop ship, the "Mongolia," is quite detailed and anecdotal. The diary ends with an entry for May 10, 1918, while Smith is convalescing from a knee operation. Diary entries for October 8-10, 1917, and February 9-13, 1918, laid in back of diary (18 leaves.)