Both the purpose and practice of war have changed in modern times. The Westphalian system limited warfare to combatants and to limited areas.
Modern war includes non-combatants and unlimited areas.
Political and military leaders need more than ever to look for non-violent solutions to political disputes. Problems caused by overlapping command structures necessitated many organizational changes throughout the war. The Comanche Elm Creek Raid in north Texas showed how poor the Texas defenses were. Adjustment to frontier army life was difficult for many middle-class army wives. The army made little accommodation for wives, and they had to improvise to survive on isolated, destitute, frontier posts.