Federalism is a system of government in which entities such as states or provinces share power with a national government. The United States government functions according to the principles of federalism.
The U.S. political system evolved from the philosophy of federalism. Remember The Federalist Papers, the essays written by Alexander Hamilton, John Jay, and James Madison between 1787 and 1788, to convince people to approve the Constitution? Federalism helps explain why each state has its own constitution and powers such as being able to choose what kind of ballots it uses, even in national elections. The national government oversees the election results, but each state controls its own voting procedures.