Workers leveling Beacon Hill, Boston; a view from the north towards the Massachusetts State House. In 1787 Charles Bulfinch designed the Massachusetts State House. Its construction was completed in 1795, replacing the Old State House in the center of Boston. In 1780 The Mount Vernon Proprietors group was formed to develop the area when the city's neighborhoods could no longer meet the needs of the growing number of residents. Nineteen acres of grassland west of the State House was purchased in 1795, most of it from John Singleton Copley. The Beacon Hill district's development began when Charles Bulfinch, an architect and planner, laid out the plan for the neighborhood. Four years later the hills were leveled, Mount Vernon Street was laid, and mansions were built along it. One of the first homes was the Harrison Gray Otis House on Cambridge Street. Lithograph by J.H. Bufford, 1858; after a drawing by J.R. Smith of 1811-12.