When the United States attacked British North America, most British forces were engaged in the Napoleonic Wars. Thus, British North America had minimal troops to defend against the United States, which had a much larger military force but was initially poorly trained. For most of the war, British North America stood alone against a much stronger American force. Reinforcements from Britain did not arrive until 1814, during the final year of the war. The repelling of the American force helped to foster Loyalism in the colonies that later became Canada.