Federalist

Webster's Dictionary

(n.) An advocate of confederation; specifically (Amer. Hist.), a friend of the Constitution of the United States at its formation and adoption; a member of the political party which favored the administration of president Washington.

The Nuttall Encyclopedia

A name in the United States for a supporter of the Union and its integrity as such; a party which was formed in 1788, but dissolved in 1820; has been since applied to a supporter of the integrity of the Union against the South in the late Civil War.