The Battle of Queenston Heights was the first major battle in the War of 1812. Resulting in a British victory, it took place on 13 October 1812 near Queenston, Upper Canada (now Ontario).

The battle was fought between United States regulars with New York militia forces, led by Major General Stephen Van Rensselaer, and British regulars, York and Lincoln militia and Mohawk warriors, led by Major General Isaac Brock and then Major General Roger Hale Sheaffe, who took command after Brock was killed.

The battle was fought as the result of an American attempt to establish a foothold on the Canadian side of the Niagara River before campaigning ended with the onset of winter. The decisive battle was the culmination of a poorly-managed American offensive and may be most historically significant for the loss of the British commander.

Despite their numerical advantage and the wide dispersal of British forces defending against their invasion attempt, the Americans, who were stationed in Lewiston, New York, were unable to get the bulk of their invasion force across the Niagara River because of the work of British artillery and the reluctance on the part of the undertrained and inexperienced American militia. As a result, British reinforcements arrived, defeated the unsupported American forces, and forced them to surrender.

The War of 1812 (18 June 1812 – 17 February 1815) was a conflict fought by the United States of America and its indigenous allies against the United Kingdom and its allies in British North America, with limited participation by Spain in Florida. It began when the US declared war on 18 June 1812 and, although peace terms were agreed in the December 1814 Treaty of Ghent, did not officially end until ratified by Congress on 17 February 1815.Tensions originated in long-standing differences over territorial expansion in North America and British support for Native American tribes who opposed US colonial settlement in the Northwest Territory. These escalated in 1807 after the Royal Navy began enforcing tighter restrictions on American trade with France, exacerbated by the impressment of men claimed as British subjects, even those with American citizenship certificates. Opinion was split on how to respond, and although majorities in both the House and Senate voted for war, they divided along strict party lines, with the Democratic-Republican Party in favour and the Federalist Party against. News of British concessions made in an attempt to avoid war did not reach the US until late July, by which time the conflict was already underway.

At sea, the far larger Royal Navy imposed an effective blockade on US maritime trade, while between 1812 to 1814 British regulars and colonial militia defeated a series of American attacks on Upper Canada. This was balanced by the US winning control of the Northwest Territory with victories at Lake Erie and the Thames in 1813. The abdication of Napoleon in early 1814 allowed the British to send additional troops to North America and the Royal Navy to reinforce their blockade, crippling the American economy. In August 1814, negotiations began in Ghent, with both sides wanting peace; the British economy had been severely impacted by the trade embargo, while the Federalists convened the Hartford Convention in December to formalise their opposition to the war.

In August 1814, British troops burned Washington, before American victories at Baltimore and Plattsburgh in September ended fighting in the north. It continued in the Southeastern United States, where in late 1813 a civil war had broken out between a Creek faction supported by Spanish and British traders and those backed by the US. Supported by American militia under General Andrew Jackson, they won a series of victories, culminating in the capture of Pensacola in November 1814. In early 1815, Jackson defeated a British attack on New Orleans, catapulting him to national celebrity and later victory in the 1828 United States presidential election. News of this success arrived in Washington at the same time as that of the signing of the Treaty of Ghent, which essentially restored the position to that prevailing before the war. While Britain insisted this included lands belonging to their Native American allies prior to 1811, Congress did not recognize them as independent nations and neither side sought to enforce this requirement.