United States soldier
Infantryman Thomas Philip Murphy, my great-uncle, was wounded eleven times during the Meuse-Argonne Offensive in France, and died in the evacuation hospital there in October 1918. He was 23. He was eventually buried in Arlington, Mass. in 1921. My father used to tell a poignant story of Thomas’ mother going to meet her son’s casket at the train station and welcoming him home.

British soldier (from Newfoundland)
My first cousin twice removed Bernard Cleary enlisted in the Newfoundland Regiment and died along with almost the entire regiment at Beaumont-Hamel on 1 July 1916. If you get a chance to see the exhibit “Beaumont-Hamel and the Trail of the Caribou” at The Rooms in St. John, definitely go.

British sailor (from Ireland)
My great-great-uncle Timothy Deasy lied about his age to join the British Royal Navy in 1897 when he was 15 years old. He served in the Royal Navy until he died with about 900 other people aboard the HMS Defence, an armored cruiser sunk during the Battle of Jutland in 1916. The wreck of the Defence has since been found by divers in the North Sea; it is currently protected as a war grave under the British Protection of Military Remains Act.

Sources
Cambridge World War I Memorial Plaques, Cambridge Public Library. Digital images. Digital Commonwealth: Massachusetts Collections Online.
Deasy, James. Family history and ledger. 1895. Privately held.
Death notice for Thomas P. Murphy, Cambridge Chronicle, 16 July 1921, p. 3. Digital image. Cambridge Public Library, Historic Cambridge Newspaper Collection (http://cambridge.diconsulting.com : accessed June 2015).
England. Admiralty: Royal Navy Registers of Seamen’s Services. Access via “Discovery.” Database with images. The National Archives.
Glavine, James. Our People . . . Our Church: Sts. Peter and Paul Parish, Harbour Main, Newfoundland, 1857-1982. Harbour Main, Newfoundland, 1983. 112.
“HMS Defence (1907).” Wikipedia.
United States. World War I Military Cablegrams, Main Series, War Department to AEF HQ, #2683. National Archives. Database. Footnote.com. (Which has since become fold3.com)