The British policy of trying to interdict neutral trade with France by stopping merchant ships on the high seas inevitably alienated the United States of America. On 18th June 1812, the US Congress declared war on Britain and ordered a three-pronged offensive into Canada. It did not go well. In the West the Americans were defeated by a mixed force of Canadian militiamen and British regulars, losing Forts Mackinac and Dearborn (at either end of Lake Michigan) as well as Detroit. In the centre, along the Niagara frontier, nearly 1,000 American troops were forced to surrender at Queenston (Canada), while the attack in the East, towards Montreal, soon petered out. A renewed offensive in 1813 fared little better in the area to the East of Niagara, where the British counter-attacked and burned Buffalo, although in the West, after a US naval victory on Lake Erie, American troops did force a British withdrawal.
In 1814 the Americans tried to exploit their slight advantage by committing a 3,500 man army to the Niagara frontier. Despite a victory over British regulars at Chippewa River (5th July), the Americans were stopped at the Battle of Lundy’s Lane (25th July) and forced to pull back. A month later, a British amphibious force entered Chesapeake Bay, sailed up the River Potomac and attacked Washington, burning the Capitol and other government buildings. A similar attack on Baltimore was met with more effective defence in September, upon which the British sailed back to the West Indies. But they soon returned this time to attack New Orleans with over 8,000 veteran troops newly arrived from Europe.
On 23th December, they landed at Bayou Blenvenu and marched towards New Orleans along a narrow route between the River Mississippi and an area of swampland. They soon encountered defences manned by 5,700 American troops under Major-General (and future President) Andrew Jackson. A frontal attack by the British on 8th January 1815 was disastrous (they suffered over 2,000 casualties before withdrawing), but the battle was in fact unnecessary. Two weeks earlier, peace terms had been negotiated at Ghent, although it took time for the news to cross the Atlantic. The Battle of New Orleans was a pointless end to a pointless war.