The causes of the Anglo-American War of 1812 began when the British navy seized more than 250 American merchant ships in 1794, on their way to the French Indies. Many Americans called for declaring war on Britain, recalling the unhealed wounds of the War of Independence.
To avoid war, President George Washington sent John Jay to London, in order to close an agreement to satisfy all parties. The Jay Treaty, as it was called, prevented war, but the most intransigent American faction of Jeffersonians directly opposed to the agreement.
There was control until 1807, when Emperor Napoleon ordered the Continental Blockade against British products which strain relations. Britain also forbade any trade with the French, and soon serious disputes, especially when HMS Leopard grabbed five deserters from the USS Chesapeake.
As a measure to avoid war, President Thomas Jefferson ordered the embargo on all English and French products, with the hope that both countries would soften their mutual positions. The embargo was such a failure that ended in economic depression.
In 1810, Americans elected a Congress composed of a fierce group of expansionists, almost all of the western states. These "war hawks" as they called themselves, pressured the conquest of Canada to counter London.
The invasion of Canada resulted in a humiliating defeat, and British troops not only repelled the Americans, but the British came to occupy Washington DC, burning the Capitol, the White House, and other government buildings. Fortunately for Americans, the naval war itself was somewhat more successful, including some important victories.
In the end, the British were defeated at Lake Champlain and Fort McHenry, in Baltimore. However, the United States went bankrupt and had to decree the highest taxes in its history to recover.
The positive result was the strengthening of American nationalism. Andrew Jackson ascended as a hero. American patriotism and courage put down roots in a proud and determined people.