President James Madison signed Congress’s Declaration of War against Britain on June 18, 1812, inaugurating the unimaginatively named War of 1812. As Fred already noted, it was approved by a close vote in Congress — 74–49 in the House, 190-13 in the Senate. The vote was highly partisan — not one of the 39 minority Federalists voted for it, most of Madison’s Republican party approved. The first casualties of the war would be Americans, killed by other Americans, in the Baltimore riots of June and July, when Republican mobs twice destroyed the headquarters of a local Federalist newspaper. Madison is often credited with refusing to impose a sedition law during war-time; his attitude towards censorship in the private sector was more ambiguous. When the Baltimore City Council issued a report whitewashing the violence, Madison approved it.
The United States was spectacularly unprepared for war. The adolescent Navy, which had seen action in the Quasi War with France and the first Barbary War with Tripoli, was in good shape, though small. The army was described by Winfield Scott, then a lieutenant colonel, as “imbeciles and ignoramuses. . . . The old officers had, very generally, sunk into either sloth, ignorance, or habits of intemperate drinking.” Younger officers were “swaggerers, dependants, decayed gentlemen, and others ‘fit for nothing else.’” Scott’s judgment would be confirmed when we lost Detroit to an inferior British force.
Our navy won a few brilliant early victories, and the army got much better over time (thanks to officers like Scott). The partisan rancor never diminished, and would lead Federalist enragés to the brink of secession.
For further reading, George C. Daughan has just published 1812: The Navy’s War. When I was writing James Madison I relied on Donald R. Hickey’s The War of 1812. The classic is of course History of the United States of America During the Administration of James Madison, to which should be added History of the United States of America During the Administration of Thomas Jefferson. That’s a big read — 2,600 pages — with a number of limitations: Adams somewhat overdoes diplomacy (it was his avocation) and grossly ignores DeWitt Clinton (Madison’s rival in the election of 1812). There is also a consistent archness which can be as grating as Gibbon. But Adams keeps a dozen balls in the air at the same time, he can be funny, savage and savagely funny, and underlying the archness is a deep layer of appreciation, almost patriotism. The chapter “American Ideals” from Jefferson is a gem.