The last American war against the British was the War of 1812.
Explanation:
The War of 1812 was a military conflict between the United States on the one hand and Great Britain and its North American colonies in present-day Canada on the other, which took place from 1812 to 1815. The war started after Thomas Jefferson - president of the US - wanted to stay outside the European conflicts. He wanted to devote himself to building the new nation, doubling US territory under his rule. The United States also wanted to continue to trade unhindered with Napoleon Bonaparte's France and with Napoleon's other countries on mainland Europe. Britain did not want to recognize this neutrality right, so in response Jefferson announced a trade embargo.
In 1812, Jefferson's successor James Madison declared war on Great Britain with the main objective of breaking the Indian-British coalition and conquering all of Canada, or, as the Americans saw it, liberating it. During this war, which did not really go according to the wishes of the US, on April 27, 1813 York - the then government center of Canada and later Toronto - was burned down by the Americans; on the night of August 24 to 25, 1814, the British occupied Washington and several public buildings, including the White House, were burned down.
This war was finally ended with the Treaty of Ghent, which was drafted in 1814 and ratified by the Americans in 1815. It did not curb the English supremacy at sea. Nor did the US succeed in conquering Canada. The British did stop supporting their Indian allies so that the colonization by the Americans of Indian territory could no longer be prevented by the original inhabitants. Furthermore, a real American national feeling emerged during and after the conflict, reinforced by various heroic stories from the war. This led to the next president, James Monroe, proclaiming the Monroe doctrine named after him. As a result, until the Spanish-American War in 1898, the US kept out of any European conflict and devoted itself to its expansion of power on the American continent.
