During the 1870s and 1880s, mansions were built along Massachusetts Avenue, one of Washington's grand avenues, and townhouses were built throughout the neighborhood. In 1872, the British built a new embassy on Connecticut Avenue, at N Street NW. Stewart's Castle was built in 1873 on the north side of the circle. By the 1920s, Connecticut Avenue was more commercial in character, with numerous shops. Some residences, including Senator Philetus Sawyer's mansion at Connecticut and R Street, were demolished to make way for office buildings and shops. The Patterson House, at 15 Dupont Circle, served as a temporary residence for President Calvin Coolidge while the actual White House was being repaired in 1927. In 1933, the National Park Service took over administering the circle, and added sandboxes for children, though these were removed a few years later.