What difference did the war make? That depends on the point of view. The Treaty of Ghent officially ended the war, but it changed little. Neither side lost or gained territory or other concessions.
Great Britain was satisfied with the status quo. For most of the war it had held the upper hand, including a successful invasion of Maryland and the occupation of the US capital city. Britain retained her North American possessions and actually gained new loyalty within the Canadas where the war united French-speaking and English-speaking colonies against American aggression. War weary from decades of fighting elsewhere, the British decided that victory over the distant United States was not worth the mounting cost.
For Upper and Lower Canada, the War of 1812 was a victory. The British North American colonists united with Great Britain and American Indian allies to resist the attempt by the United States to conquer its northern neighbor. The war reinforced the colonial Canadas’ ties to Great Britain while inspiring a movement that eventually led to an independent Canadian Confederation.
The story was very different for American Indians, most of whom allied themselves with the British. They experienced some of the most brutal fighting of the war along the western and southern frontiers and in Upper Canada. Their great leader Tecumseh died in battle, and with him died the vision of a confederacy of native nations united to protect their territory and traditional ways of life. The Treaty of Ghent did nothing to restore Indian lands, and with the end of the war they lost their British allies. There was nothing to stem the devastating tide of westward expansion that followed the war.
For the United States of America, the war was a coming of age. The young upstart nation was divided by political and sectional bickering when it brashly declared war on Great Britain in 1812. It was badly bruised on the homefront over nearly three years, but it emerged in 1815 a stronger, more united nation. Citizens began to refer to themselves as Americans, rather than citizens of a particular state, such as Virginians or Marylanders. Their country had new heroes, new symbols, new stories of patriotism, and a new generation of leaders.
The “Era of Good Feelings” that followed the War of 1812 in the United States energized the nation. Its new-found confidence stimulated developments in manufacturing, transportation, central banking, national defense, and particularly territorial expansion. The war also brought new respect to the young nation from many of the older more powerful nations of the world.
The costs of the war are impossible to calculate. For a nation forever changed by the experience, the benefits were priceless.