19: The event that was influenced by the ideas of the American Revolution was the Boston Tea Party. A boycott made by businessmen from the colonies on British tea imports in the port of Boston. It happened as a protest against the tax exemption on British Tea on American soil. This event laid the path for further actions that were taken by the "Sons of Liberty" that would lead to the American Revolutionary War.
20: The American Revolution started a wave of political upheavals throughout Europe that changed the political landscape of the region until what it has become nowadays. The French, who were inspired by these events, led their own revolution 2 decades after the independence fo the United States.
21: The system of checks and balances was created in order to maintain an equilibrium in power among the 3 branches of the Federal Government, which are Executive, Legislative, and Judicial branches.