I happened upon the following earlier today. It is worth remembering that the U.S. has usually had a party opposed to war when it has gone to war. It was true in the American Revolution, in the War of 1812, in Mexican War, Civil War, etc.
“After all, victory will do more than any thing else can, towards reconciling the country to this just war. The glory of a nation is, and must be, the nation’s property, not a party’s. History, poetry, and the canvass, are of no party. Fifty years hence, ten years hence, the victories which we have gained, and the greater ones which I trust we will gain, will be celebrated in orations, in histories, in songs, in the epick, with the pencil, neither as democratic or foederal victories, but as American, as national triumphs and the sources of our national glory.”
Richard Rush to John Adams, September 25, 1813
Rush serving as Comptroller of the Treasury at the time, early in the War of 1812