The British were also fighting the French or on the verge of having another war with France. Which made fighting the colonists too expensive to continue. Besides they still had Canada as a place they could station troops and keep us in check. The War of 1812 was the revolutionary war, part 2. But, by then any chance of getting us back into the empire was gone. The same thing happened, too many fronts to fight a war on, Napoleon was giving the English Government a great deal of concern. Plus, they finally decided that America as an independent trading partner was better for all concerned.