The system of checks and balances included in the U.S. Constitution was proposed and explained by James Madison. In Federalist No. 51, Madison discussed how the Constitution's structure divided the national government into three branches—legislative, executive, and judicial—to prevent any one branch from becoming too powerful. Each branch was given the power to check the others' powers in order to maintain balance and protect liberty. Madison emphasized that ambition must be made to counteract ambition, meaning the different branches would use their powers to resist encroachments by the others.
This idea was influenced by political theorists such as Montesquieu but was chiefly articulated and proposed by Madison and the Framers during the drafting of the Constitution.
