On the night of June 23-24, 1812, the leading echelons of Napoleon's Grande Armée — roughly 420,000 troops in the initial crossing, with second-echelon reinforcements eventually bringing the total mobilized for the campaign to more than 600,000 — crossed the Niemen River and marched east into Russia. Five months later, what remained of the army straggled back across the same river: somewhere between 25,000 and 100,000 effectives by various accounts (the lower figure for those still in formation, the higher for everyone who made it back including stragglers), the rest dead from combat, starvation, typhus, frostbite, or simple exhaustion. The campaign is the textbook case of a continental land power overextending into the geographic depth of another continental land power.

That same year and across the Atlantic, the United States declared war on Britain — the War of 1812 — and the conflict played out as a collection of naval engagements on the Great Lakes, raids along the U.S. coast, the burning of Washington in August 1814, and the Battle of New Orleans on January 8, 1815 (fought after the Treaty of Ghent had been signed on December 24, 1814 but before the U.

S. Senate ratified it on February 16, 1815 — the war was not legally over when the battle took place).