Upon declaring against the British, the War Hawks' made their slogan "On to Canada!" a reality. With forces outnumbering the British almost 35 to 1, they expected a quick and easy victory, an end to the British in the New World, and vast new landholdings for the US. American tactics, with a division of its forces into segments at Detroit, Niagara, and Lake Champlain, were idiotic at best, and disastrous in application. The British-Canadian forces, under the capable command of General Isaac Brock, stayed back and concentrated on defenses that the divided American troops could not overwhelm. The Americans were unable to break British Canada's chain of supply or dent its defenses. After repelling the American invasion, Brock pushed the fighting onto American territory. On August 15, his forces captured Detroit, a key to control of the Great Lakes region. On October 13, American troops made a second attempt at Canada, resulting in the Battle of Queenstown Heights. The British forces under Brock once again p ushed back the Americans, though Brock himself lost his life.
On August 19, with the land war going terribly, the USS Constitution, commanded by Isaac Hull, routed and captured the British frigate Guerriere. Besides raising American morale, the battle created an American legend: a cannonball shot from the Guerriere bounced off the side of the oak Constitution, and the ship forevermore owned the nickname "Old Ironsides." The victory of the Constitution set a trend, throughout 1812, the heavily gunned American ships consistently mastered the more lightly armed British vessels with which they came into conflict. In addition, American privateers, privately owned ships endorsed by the government to act as pirates, successfully harassed British trading vessels
On the American side, the land War of 1812 was a generally ragged, ill-fought war. The War Hawks had been excited to rush in, but poor planning typified the operations from the start. As it entered the war, the US was dramatically divided (with much of New England against the war), and fielded an untrained, hurriedly raised army comprised for the most part of amateurs. Even the regulars had little training or discipline. A large proportion of soldiers were from local militias, who were legendary for their unreliability in battle. Several of the American generals were old holdovers from the Revolutionary War, who had long lost whatever brilliance they formerly could call their own. The attack Canada set the pattern of ineptitude. Military historians largely agree that the best strategy would have been a full- scale assault on Montreal, a center of British power. Capturing Montreal would have divided the British and hopelessly damaged their supply and communication lines, as well as their morale. Instead, American tacticians foolishly divided their forces three ways, fighting on several fronts. The division of American forces made them all the easier for British-Canadian troops to push them back.
The British, on the other hand, had been busy fighting Napoleon for over ten years. British soldiers were battle-hardened veterans, and British commanders had a great deal of experience, most of it quite recent. Throughout the war, British and Canadian forces would fight quite well, especially in fighting along the US-Canada border, where British ground troops proved vastly superior to American forces. General Isaac Brock is noted for being an especially meticulous planner and skillful tactician. Furthermore, Brock was famous for his harshness towards mutineers and deserters, who he often shot himself. Although he had no sympathy for deserters, he was amiable enough around his men, who respected and even liked him. As a result, Brock's units had high morale and were very dependable. With the Napoleonic Wars going on in Europe, Brock was afraid that his stationing in the New World meant that he would not see much active duty, which would give him fewer decorations. When the War of 1812 broke out, and he got a chance to command troops in battle, he couldn't have been more pleased.
In contrast to the debacle of the land war, despite the US' vast advantages in terms of numbers, the US successes at sea, where Britain supposedly ruled supreme, were rather surpising. Though the victories at sea held less importance than the losses on land, those victories did provide the US with a good measure of morale to muster a continued effort.