The eighteenth century? Age of Napoleon?
Yes, at the time of Napoleon, in my opinion, arose the first approximation of what could be considered “national wars.” When almost the entire nation is drawn into the affair, or even entire nations, a large amount of people are drafted for military service and an attempt is made to subject industry and agriculture to the interests of the military. When movement by rail was invented, it became possible to quickly transfer a large number of soldiers from one place to another, and snow and dirt become a tactical question, not a strategic one. The same thing happened at sea. The fleet was no longer dependent on the wind and was able to sail, wherever and whenever the admiral wanted. Agricultural development has allowed a much smaller amount of farmers to feed a much larger group of people. Add to that the trains and ships for transporting goods, and the army, being on a campaign, gets everything it needs.
Of course, this is accompanied by a change in the perception of people concerning what you can expect and what is permissible in war. For centuries, looting remained an intrinsic right of a soldier during the campaign. The people mourned the losses, but no one believed that the soldiers had stepped over the line of what was allowed. However, over the centuries following the Napoleonic wars, the notion arose that civilians and civilian property cannot be touched. Of course, neither robbery nor looting has disappeared, but people, at least civilians, have come to believe that the war is a military affair and should not affect them.
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