140 Montrose Avenue is a 2 1/2 story, 3 bay, rectangular plan, Italianate, wood frame, residential building. Constructed c. 1870, the clapboard-clad building features a front-facing, centered cross gable roof, projecting from a side-gabled main roof. Additional architectural details include bracketed crowns on the 2/2 windows, overhanging bracketed eaves, a round-headed window in the gable apex, and a recessed arched entryway with leaded fanlight and sidelights. 140 Montrose Avenue is one of the oldest houses in the Montrose area, appearing on the 1873 map of land owned by John Vose and Lewis Taylor. In 1873, the house was owned by Robert H. Thayer. Through 1911, it was owned by Harriet F. Thayer. By 1928, the house was owned by Alexander M. Craig. The Thayers were one of the most prominent families of 19th century South Orange, and socialized with the Voses and other important Village families.