Description: Rose Hill is a 2 1/2-story brick house, five bays wide on the main or south facade of its main block. The center three bays are covered by large two-story pedimented portico supported by fluted Doric columns on the first floor and Ionic columns on the balustraded second floor. The Doric columns support an entablature of triglyphs and dentils. The pediment, with a modillion cornice and raking cornice, holds a traceried fanlight in the tympanum. To either side of this large pediment, the roof is pierced by a dormer window with round-arch and a parapet. A flush chimney rises from each gable end of the main block. The central entrance on each floor is flanked by two windows on either side, with 9/9 lights on the first floor and 9/6 on the second. The first-floor entrance has 4-light sidelights and a 4-light transom, and the door is flanked by slender columns. The second floor door is flanked by 4-light sidelights and surmounted by a transom of two rows of 3 lights each. The north facade of the main block has similar fenestration, but the pediment rests on the roof proper, and above the first-floor door is a slightly lowered 9/6 window. This entrance is sheltered by a one-bay porch. To the west gable end is attached a two-story brick wing, three bays wide and two deep, with a central entrance with 2-light transom. Windows on this wing are 6/6 on the first floor and 9/6 on the second. A flush brick chimney rises from the west gable end. This wing is flush with the north or rear elevation, but recessed from the front or south by a bay. A shed-roofed porch spans the north side of the wing. Roofs are covered with standing seam metal. Significance: The design of the house is a transitional style, between the late Georgian of Tidewater Maryland, and the Greek Revival style. Thomas Johnson (1732-1819), a close political associate, honored friend, and champion of George Washington whose eulogy he delivered, chose Rose Hill as his retirement home during the end of the 18th century. His political career included being the first elected Governor of the State of Maryland (1777-1779); serving as an Associate Justice of the United States Supreme Court (1791-1793); nominating George Washington as Commander-in-Chief of the Continental Army. Johnson helped to form, and was instrumental in the passage and adoption of, the first constitution for the State of Maryland in 1776, as well as assisting in framing the United States Constitution in 1788. He served as a commissioner on the Board of Commissions responsible for authorizing Pierre L'Enfant, architect, to plan Washington, D.C., the federal city. He declined an invitation to become the United States Secretary of State under President Washington. Rose Hill expresses an expanded, comfortable country living near Frederick during the Federal period, after the American Revolution and during the growth of the new nation. Erected. c. mid 1790s by his daughter and son-in-law, the Governor retired here during the last years of his life.