The correct answer to this open question is the following.
The revolution that created the first nation that had gained independence from European power was the American Revolutionary War.
This war was fought from 1775 to 1783. The Continental Army, led by General Gorge Washington, defeated the English troops to gain independence. The Treaty of Paris signed on September 3, 1783, represented the official ending of the war. No more heavy taxation and injustices from the British monarchy.
