An attack on Canada in the Detroit area was begun by the United States in 1812. This early assault ended in the defeat of the American forces and the capture of Detroit by the British. Another American force that attempted an invasion of Canada across the Niagara River was defeated that same year at Queenston (near Niagara).

The U.S. Navy gave a good account of itself in a number of single-ship engagements. Notable American successes in 1812 included the capture of the Macedonian by the United States and victories by the Constitution ("Old Ironsides") over the Guerrire and the Java. The U.S. Navy, however, had only 14 war vessels, and was too small to prevent the British Navy, which could call upon 1,048 war vessels, from imposing an effective blockade on American ports. The blockade destroyed American trade and eventually contributed to the desire of the United States to end the war. Lone American warships and privateers were highly effective during the war as commerce raiders, and the British lost many merchant ships to American attacks.

Detroit was recaptured by the Americans after Captain Oliver Hazard Perry achieved a brilliant naval victory on Lake Erie in 1813. Troops under General Harrison then defeated the British and Indians in the Battle of the Thames in Canada. Tecumseh was killed in this engagement.

In July, 1814, the United States attempted another invasion of Canada in the Niagara region. General Winfield Scott led a force that defeated the British in the Battle of Chippewa on July 5th. The American advance, however, was halted July 25th at the Battle of Lundy's Lane.

The British in 1814 were able to fight the war more vigorously, using troops and ships released by their victory over Napoleon the same year. They launched an invasion of New York in August, but the invading army was forced to turn back to Canada when an American naval force under Lieutenant Thomas Macdonough defeated a British fleet on Lake Champlain, depriving the army of its naval support. Another large British force was turned back from Baltimore after it had burned Washington, D.C. New Orleans was the next major British goal. Major General Andrew Jackson won the Battle of New Orleans in January, 1815; communications were so slow that neither Jackson nor the British knew that their countries had signed a peace treaty at Ghent, Belgium, on December 28, 1814.