The clapboarded Mulford-Lyons House is a Federal-style expression of New England saltbox houses found on eastern Long Island. Merchant Sylvanus Mulford built the house during the Federal style's popularity in 1818, the year he married Fanny Jessup. Both were from old eastern Long Island families. The twin entrances with attenuated fluted pilasters and elliptical fanlights are typically Federal. One entrance opened to the Mulford store, the other to the family's residence. The barn at the rear of the lot was built in 1860. A later frame addition connected the house and barn in a fashion that farmers adopted in northern New England after 1830. After Mulford relocated to the new business district along Public Avenue in the early 1830s, Jerre Lyons from Massachusetts bought the building.