One of six attached houses townhouses between 70-75 Beacon Street, this stately granite-faced residence was built concurrently with its neighbors in 1828 on speculation for the Mount Vernon Proprietors, a group of wealthy Boston businessmen who helped develop Beacon Hill into the posh, architecturally significant neighborhood it is today. The Mount Vernon Proprietors knew how important Beacon Street was as the entry into the neighborhood, and thus, hired Boston’s premier architect, Asher Benjamin, to design the row. When completed, all of the houses were identical, but throughout the 19^th and 20^th centuries, they all deviated from the original design, some gaining additional floors, others adding bay windows, but all together form a cohesive and architecturally significant span of houses. Completed in 1829, the corner dwelling is known as the Greenough-Dwight House and it retains its original three-story rusticated granite façade with segmental arch openings. The major change to the exterior of the Greenough-Dwight House is the addition of the ornate wood oriel window with iron cresting in 1874, the oriel and facade feature the iconic purple windows, which became a status symbol in the 20^th century. The story goes, that between 1818 and 1824, an English company sent shipments of glass that contained too much manganese oxide into Boston Harbor. After being exposed to sunlight for an extended period of time, the manganese oxide in the glass began to turn purple creating the colored panes we love today. Over time, many panes broke or were replaced, creating the checkerboard appearance on so many windows, but many owners in the 20^th century had imitation purple glass installed as a marker of wealth and prestige, like in this house and bay, which were built after the period that the glass was brought over from England. My favorite in the row, the Greenough-Dwight House shines with its granite facade and brick end wall, with panes reflecting the sun off her violet glass windowpanes.