Simeon Smith's two houses introduced high-style aspirations into frontier Champlain Valley. Smith was a wealthy physician and land speculator from Sharon, Connecticut, where his stone mansion, Weatherstone (1765), was finished with interior detailing apparently by joiner William Sprats in the 1780s. By 1787, due to business embarrassments, Smith was pursuing a new start in western Vermont, where he became a land and mill owner, state representative, judge, and one of the wealthiest citizens of Rutland County.
In 1789 he began one of the earliest great houses in western Vermont on land in what is now West Haven. The resulting Georgian-plan mansion was grand in size, though not necessarily in detail: the expressed girts and summer beam of its parlor, the enclosed staircase, and the eleven-inch lapped boards of the exterior sheathing reflect vernacular traditions. An original eaves projection across the main front of the building, carried on full-height single columns that form a shallow porch, suggests conceptual ties to the Hudson Valley, though the porch's builder more likely came from Connecticut. In the late 1790s Smith had some parts of the house finished in a more sophisticated style. Possibly at Smith's invitation, joiner William Sprats settled in nearby Hampton, New York, in 1797, ultimately to move to West Haven. For Smith he appears to have created the shouldered surround of the front door and the superb woodwork of the two principal parlors—with his signature modillion and dentil cornices, and richly detailed Doric and Ionic orders. He may also have introduced the slender colossal porch columns, similar to ones he employed on the Litchfield County Courthouse (1797) and the meetinghouse in Georgia (1802; demolished). In 1937 Rutland-based Colonial Revival architect Payson Webber extensively renovated the mansion, approximating its lost portico with an extended and flared roofline and a rhythm of paired and single columns.
Northeast of the mansion, Smith built a guesthouse annex in 1798, where his second wife, Catherine, could entertain their many visitors. The Federal I-house is Vermont's most complete and intact example of William Sprats's work. The gable-roofed, clapboarded exterior is crowned with a richly textured modillioned and dentiled cornice above a plain frieze, echoed over the door and sidelights below. Inside is a noteworthy second-floor ballroom that was originally reached by a staircase in a now-replaced ell. The ballroom's walls are framed out to an eighteen-inch thickness, with shuttered window reveals and built-in window seats. A fireplace framed with fluted Doric pilasters and triglyph frieze below a shouldered overmantel and an articulated modillioned and dentiled cornice carrying a coved ceiling complete a room that is the equal of Sprats's finest Connecticut interiors.