Robert Jones did not have enough specially trained surgeons in the UK to staff the orthopaedic units he proposed. However, his problems were significantly eased when the United States entered the war in 1917 and sent surgeons trained in orthopaedics to serve alongside their British allies. Robert Osgood, whom Harry had met in Boston before the war, and who had served with the Harvard Surgical Unit in France in 1915 was appointed deputy to Robert Jones. Osgood was instrumental in the formation of the British Orthopaedic Association in February 1918.
The material contained in the file relates largely to the diary he wrote during the first world war while serving in the American Ambulance Hospital and US Army Medical Corps in France. During his service in France, Osgood made important contributions to the orthopaedic care of the wounded and improved methods of splinting and transportation. The file contains photocopies of typescript extracts from the diaries for March to July 1915, June to July 1917, and April to May 1918. It also includes notes and correspondence relating to Robert Osgood and his diaries, correspondence relating to the deposit of Platt's correspondence with Osgood in the Countway Library, and a copy of John Adams' Robert Osgood Lecture with related correspondence, May 1985. The file contains correspondence with Ellen Jennings, Osgood's daughter, who became friends with Platt.
See also correspondence relating to the Osgood Diaries in PLA/7 and also the file relating to Platt's visit to USA 1976 during which he attended the first Robert Osgood Memorial Lecture (PLA/10/3/6).