The United States fought against the British in the American Revolutionary War. In July 1776, the United States declared their independence from Britain. Before that, the colonists who over time had migrated to the United States for various reasons including religious freedom and making a living by acquiring farmland, these colonists were still citizens of Britain. They had to pay taxes to Britain and this lasted for many years.
The taxes would increase over time, but the colonists could not participate in Parliament to make these decisions about how much to tax the colonists. Eventually, the two countries went to war. After the war, United States became its own country. They established their own government which proved difficult and the citizens eventually became happy.