In pictures, the Great War appears to be between worlds. Some of the old ways were present but we were mechanized and industrialized by then. Horses were used at the start of WW2 during the German blitzkrieg of Poland but WW1 saw much more horse action. Hollywood even made a recent movie about a WW1 soldier and his horse with the completely unimaginative title "War Horse". The Jeep would be their replacement for moving high officers around and the helicopter would become our cavalry..