High Street meets Spring Street at the McLellan-Sweat Mansion, sometimes called the McLellan House. It forms the rear component of the Portland Museum of Art complex and is accessed through the museum's main entrance at Congress Square. Built in 1800–01, this house was designated a National Historic Landmark in 1970 as a well-preserved Federal style brick townhouse.
Look at the three-story brick structure: a low-pitch hip roof sitting on a granite foundation, its brick laid in Flemish bond. The main facade facing Spring Street is five bays wide, centered on an entrance sheltered by a semicircular portico supported by Doric columns and topped by a balustrade. The entry is flanked by sidelight windows and capped by a fanlight, with a Palladian window directly above on the second level.
The roofline shows a bracketed cornice and a low balustrade ringing the roof whose posts are surmounted by urns. Inside, the house follows a central-hall plan with high-quality woodwork in the public rooms of the first floor. Notice the semicircular portico, the Palladian window above it, and the urn-topped balustrade ringing the roofline.