Military Costs of Major U.S. Wars in “constant dollars” (that is, adjusted in terms of 2008 U.S. dollars) from the American Revolution to our current conflicts. All figures represent estimated military costs only, and do not include assistance to allies, veterans benefits, interest on borrowed money, etc. The map also reports the cost of war as a % of GDP during the peak year of each conflict.
View the interactive map. Also, here’s the original data report just in case you wanted to dig deeper.