sentences:  It was designated a National Historic Landmark in 1974 for its association with Matthew C. Perry, commandant of the adjacent Brooklyn Navy Yard 1841–1843, whose opening of Japan to the west in 1854 revolutionized trade and international affairs.The building is now privately owned.The former Commandant's House is set on a bluff overlooking the western side of the Brooklyn Navy Yard, a few blocks south of the East River.