On March 31, 1854, the or was the first treaty between the United States of America, and the Empire of Japan, then under the administration of the Tokugawa Shogunate. Signed under threat of force, it effectively meant the end of Japan’s 220-year-old policy of national seclusion (sakoku), by opening the ports of Shimoda and Hakodate to American vessels. It also ensured the safety of American castaways and established the position of an American consul in Japan. The treaty also precipitated the signing of similar treaties establishing diplomatic relations with other western powers.