1917
Canadian army innovations in trench warfare (careful planning, creeping artillery barrages followed closely by troop assaults, and machines guns used in indirect fire) helped to secure victories at Vimy Ridge and Passchendaele.
"Flash Spotting" and "Sound Ranging": Jan-Mar 1917
American Declaration of War: 6 Apr 1917
Billy Bishop Wins Military Cross: 8 Apr 1917
