Harry Firmstone Whelen Johnson was born in Embreeville, Tennessee on 24 April 1896, the son of Guy Roche Johnson, a steel blast-furnace design engineer, and Edith (Whelen) Johnson. When his family relocated to Bethlehem, Pennsylvania, he attended local schools there. Harry enrolled in Lehigh University where he studied chemical engineering but left school in February of 1917 to join the American Red Cross. He served for two months in France with a Norton-Harjes ambulance section. On 25 June 1917, Johnson left the ambulance service to join France's Service Aeronautique. From 1 August to 10 December 1917, he attended the aviation schools a Avord, Tours, Pau, and the G.D.E. He received his brevet on the Caudron on 1 October 1917.
On 12 December 1917, Caporal Johnson was assigned at the Front to Escadrille N. 85. He flew with that squadron until 9 January 1918 when he was assigned to Nieuport 98. On 20 January 1918 while engaged in combat against heavy odds, Johnson was shot in the stomach but managed to land his machine undamaged near a French hospital. For his coolness and courage, Caporal Johnson was awarded France's Medaille Militaire and Croix de Guerre with Palm.
On 12 April 1918 while Johnson was convalescing, he was commissioned a First Lieutenant in the U.S. Air Service. That same day, he was reassigned to the Front with SPA 168.
Lieutenant Johnson flew combat patrols with that squadron until 21 May 1918. On that date, while on a morning patrol deep into enemy lines over Suippes, Johnson flew alongside his patrol leader, Thomas Cassady, when he signaled that he was having engine trouble. Johnson banked his SPAD and volplaned out of sight of his comrades.
French ground troops later reported that around 10:30 a.m., Johnson approached the forward trenches and began frantically waving for the poilu to clear away from his landing path. He even fired his machine gun to get their attention. His landing gear snagged the barbed wire and was torn away. His SPAD aircraft "capoted" and Johnson was thrown out of his cockpit landing on his neck. Knocked unconscious with his spine fractured, he died a few moments later. Harry Firmstone Whelen Johnson was buried with full military honors at the Mont Phernet cemetery. He was 21 years old at the time of his death. In 1928 his remains were reinterred at the Lafayette Flying Corps Memorial near Paris.
[Source: "The Lafayette Flying Corps: The American Volunteers in the French Air Service in World War One," by Dennis Gordon. Schiffer Military History, Atglen, PA: 2000. Page 261.]