Timeline of United States diplomatic relations

The following is a timeline of major dates in U.S. diplomatic history, specifically the establishment or severance of official diplomatic relations, the diplomatic recognition of sovereign countries, and the opening or closure of diplomatic posts.

18th century February 6, 1778 – France recognizes the United States as an independent state with the signing of the Treaty of Amity and Commerce. August 6, 1778 – The United States establishes diplomatic relations with France. March 23, 1779 – The United States establishes a diplomatic mission in Paris. April 19, 1782 – The Netherlands recognizes the United States. The United States and the Netherlands establish diplomatic relations when U.S. Minister John Adams presents his credentials at The Hague. February 20, 1783 – The Spanish Empire recognizes the United States. April 3, 1783 – Sweden recognizes the United States as an independent state with the signing of the Treaty of Amity and Commerce. September 3, 1783 – The United Kingdom of Great Britain and Ireland formally recognizes the independence of the United States with the signing of the Treaty of Paris of 1783. June 1, 1785 – The United States and the United Kingdom establish diplomatic relations when John Adams presented his credentials as Minister Plenipotentiary to King George III. September 18, 1785 – The Kingdom of Prussia recognizes the United States with the signing of the Treaty of Amity and Commerce. June 23, 1786 – Morocco recognizes the United States. October 25, 1791 – The Republic of Genoa recognizes the United States. May 13, 1791 – Portugal recognizes the United States. The United States establishes diplomatic relations with Portugal. June 9, 1972 – Denmark recognizes the United States. September 5, 1795 – The Regency of Algiers recognizes the United States. 1797 – The Austrian Empire recognizes the United States.

19th century October 12, 1801 – The United States establishes diplomatic relations with Denmark. October 28, 1803 – The Russian Empire recognizes the United States. July 14, 1809 – The United States and the Russian Empire formally establish diplomatic relations. June 18, 1812 – The United States severs diplomatic relations with the United Kingdom in the wake of the War of 1812. August 8, 1815 – The United States and the United Kingdom re-establish diplomatic relations when John Quincy Adams presents his credentials in London as Envoy Extraordinary and Minister Plenipotentiary. June 19, 1822 – The United States recognizes Colombia. December 12, 1822 – The United States recognizes Mexico as an independent state. The United States and Mexico establish diplomatic relations. January 27, 1823 – The United States recognizes Argentina and Chile. May 26, 1824 – The United States recognizes Brazil and establishes diplomatic relations. May 2, 1826 – The United States recognizes Peru. May 21, 1827 – The United States establishes diplomatic relations with Peru. February 11, 1830 – The United States and the Ottoman Empire formally recognize each other. September 13, 1831 – The United States and the Ottoman Empire establish diplomatic relations. January 6, 1832 – The United States recognizes Belgium. June 18, 1832 – The United States establishes diplomatic relations with Belgium. September 21, 1833 – The United States and the Sultanate of Oman formally recognize each other. February 28, 1835 – The United States recognizes Venezuela. June 30, 1835 – The United States establishes diplomatic relations with Venezuela. June 16, 1844 – The United States and China formally recognize each other and establish diplomatic relations. Spring 1846 – The United States and Mexico sever diplomatic relations in the wake of the Mexican-American War. December 4, 1848 – The United States and Mexico re-establish diplomatic relations, following the signing of the Treaty of Guadalupe-Hidalgo. June 28, 1850 – The United States and Iran formally recognize each other. March 31, 1854 – The United States and Japan formally recognize each other. July 29, 1858 – The United States and Japan establish full diplomatic relations with the signing of the Treaty of Amity and Commerce. April 11, 1861 – The United States recognizes the Kingdom of Italy. The United States and Italy establish diplomatic relations. May 7, 1861 – The United States recognizes San Marino. September 23, 1862 – The United States formally recognizes Liberia. February 23, 1864 – The United States establishes diplomatic relations with Liberia. January 18, 1871 – The United States recognizes the German Empire. May 31, 1878 – The United States recognizes Luxembourg. April 7, 1881 – The United States recognizes the Kingdom of Romania. October 14, 1881 – The United States recognizes the Kingdom of Serbia. October 23, 1882 – The United States and the Kingdom of Siam establish diplomatic relations. November 12, 1882 – The United States establishes diplomatic relations with Serbia. May 20, 1883 – The United States establishes diplomatic relations with the Kingdom of Choson. March 20, 1883 – In their first diplomatic interaction, the United States and the Kingdom of Siam sign a Treaty of Amity and Commerce. June 11, 1883 – The United States establishes diplomatic relations with Iran. March 30, 1893 – The United States appoints Thomas F. Bayard as the first U.S. diplomat with the rank of Ambassador.

Early 20th century May 27, 1902 – The United States establishes diplomatic relations with Cuba. July 17, 1903 – The United States establishes diplomatic relations with Luxembourg. November 1903 – The United States recognizes Panama and establishes diplomatic relations. December 27, 1903 – The United States establishes diplomatic relations with the Ethiopian Empire. March 8, 1905 – The United States establishes diplomatic relations with Morocco. October 30, 1905 – The United States recognizes Norway following its separation from Sweden. May 3, 1909 – The United States recognizes Bulgaria. February 3, 1917 – The United States severs diplomatic relations with Germany. April 8, 1917 – The Austro-Hungarian Empire severs diplomatic relations with the United States. April 20, 1917 – The Ottoman Empire severs diplomatic relations with the United States. September 3, 1918 – The United States recognizes Czechoslovakia. January 22, 1919 – The United States recognizes Poland. May 2, 1919 – The United States establishes diplomatic relations with Poland. May 7, 1919 – The United States recognizes Finland. May 27, 1919 – The United States establishes diplomatic relations with Finland. July 26, 1921 – The United States recognizes Afghanistan. August 24, 1921 – The United States recognizes the Republic of Austria and establishes diplomatic relations. August 29, 1921 – The United States and Hungary sign a treaty establishing diplomatic relations. December 10, 1921 – The United States re-establishes diplomatic relations with Germany. July 28, 1922 – The United States recognizes Estonia, Latvia, and Lithuania. December 4, 1922 – The United States establishes diplomatic relations with Albania. June 28, 1924 – The United States recognizes the Irish Free State. October 7, 1924 – The United States establishes diplomatic relations with Ireland. February 17, 1927 – The United States establishes diplomatic relations with the newly-formed Republic of Turkey. February 18, 1927 – The United States recognizes Canada as an independent state. The United States and Canada establish diplomatic relations. July 25, 1928 – The United States recognizes the Nationalist Government of the Republic of China. November 5, 1929 – The United States recognizes the Union of South Africa and establishes diplomatic relations. January 9, 1930 – The United States recognizes the Kingdom of Iraq. March 30, 1931 – The United States establishes diplomatic relations with Iraq. May 1, 1931 – The United States recognizes the Kingdom of Hejaz and Nejd. November 16, 1933 – The United States formally recognizes the government of the Soviet Union (USSR). May 4, 1935 – The United States establishes diplomatic relations with Afghanistan. June 5, 1939 – After the Italian invasion of Albania, the United States and Albania sever diplomatic relations.

1940s January 8, 1940 – The United States establishes diplomatic relations with Australia. February 4, 1940 – The United States establishes diplomatic relations with Saudi Arabia. September 30, 1941 – The United States establishes diplomatic relations with Iceland. December 8, 1941 – Following Japan's attack on Pearl Harbor, the United States and Japan sever diplomatic relations. December 11, 1941 – Nazi Germany, Fascist Italy, and Hungary sever diplomatic relations with the United States. December 12, 1941 – Romania severs diplomatic relations with the United States. December 13, 1941 – Bulgaria severs diplomatic relations with the United States. February 16, 1942 – The United States recognizes New Zealand and establishes diplomatic relations. November 8, 1942 – Vichy France severs diplomatic relations with the United States. June 17, 1944 – The United States formally recognizes Iceland as an independent republic. June 30, 1944 – The United States severs diplomatic relations with Finland. October 16, 1944 – The United States and Italy re-establish diplomatic relations. December 1, 1944 – Following the liberation of Paris, the U.S. embassy in Paris re-opens. July 31, 1945 – The U.S. embassy in Warsaw, Poland re-opens. September 1, 1945 – The United States and Finland re-establish diplomatic relations. September 25, 1945 – The United States and Hungary re-establish diplomatic relations. October 24, 1945 – The United States joins the United Nations. January 21, 1946 – The United States and Austria re-establish diplomatic relations. October 1, 1946 – The United States and Romania re-establish diplomatic relations. July 4, 1946 – The United States recognizes the Philippines with the signing of the Treaty of Manila. The United States and the Philippines establish diplomatic relations. November 1, 1946 – The United States establishes diplomatic relations with India. August 15, 1947 – The United States formally recognizes India and Pakistan September 27, 1947 – The United States and Bulgaria re-establish diplomatic relations. February 4, 1948 – The United States recognizes Ceylon. May 14, 1948 – The United States recognizes Israel. October 29, 1948 – The United States establishes diplomatic relations with Ceylon. January 1, 1949 – The United States recognizes the Republic of Korea. January 31, 1949 – The United States recognizes Jordan. February 18, 1949 – The United States establishes diplomatic relations with Jordan. March 25, 1949 – The United States establishes diplomatic relations with the Republic of Korea. March 28, 1949 – The United States establishes diplomatic relations with Israel. July 25, 1949 – The United States joins NATO. December 28, 1949 – The United States recognizes Indonesia and establishes diplomatic relations.

1950s February 7, 1950 – The United States recognizes the State of Vietnam, the Kingdom of Cambodia, and the Kingdom of Laos. February 20, 1950 – Bulgaria severs diplomatic relations with the United States. April 28, 1952 – The United States and Japan re-establish diplomatic relations, following postwar Allied occupation of Japan. May 6, 1955 – The United States establishes diplomatic relations with West Germany. August 31, 1957 – The United States recognizes the Federation of Malaya and establishes diplomatic relations. March 24, 1959 – The United States and Bulgaria re-establish diplomatic relations.

1960s July 1, 1960 – The United States recognizes the Somali Republic and establishes diplomatic relations. September 24, 1960 – The United States recognizes Senegal and establishes diplomatic relations.