What did American gain in the Treaty of Paris?
They gained independance,and land.
The Treaty of Paris had a hand in stopping the Spanish American War. Spain gave America - Guam and Puerto Rico, and it allowed America to purchase the Philippines for $20,000,000. Cuba was freed from Spain.
There are multiple treaties of Paris. The most important in American context are the treaty of Paris of 1763 which ended the french and Indian war. The second one was the treaty of Paris of 1783 which ended the American Revolution, and the third was the Treaty of Paris or Paris Peace Conference that ended World War I.