Federalism refers to a system of government that divides power between member units and a common governing authority; the term can also be used to refer to the theory of or advocacy for this form of government. In the United States, the federal government is the common governing body to which the individual state governments belong.
The term federalist can be used to describe an advocate of a federal form of government. When capitalized, Federalism may refer to support for the historical Federalist Party (one of the two earliest American political parties) and its principles; supporters of this party were called Federalists.
