Treaty of Amity and Commerce between Siam and the United States

Signed at Sia-Yut’hia (Bangkok), 20th March, 1833
(Ratifications exchanged at Bangkok, 14th April 1836)

His Majesty the Sovereign and Magnificent King in the City of Sia-Yut’hia, has appointed the Chau Phaya-Phraklang, one of the first Ministers of State, to treat with Edmund Roberts, Minister of the United States of America, who has been sent by the Government thereof, on its behalf, to form a treaty of sincere friendship and entire good faith between the two nations. For this purpose the Siamese and the citizens of the United States of America shall, with sincerity, hold commercial intercourse in the Ports of their respective nations as long as heaven and earth shall endure.

This Treaty is concluded on Wednesday, the last of the fourth month of the year 1194, called Pi-marong-chat-tavasok, or the year of the Dragon, corresponding to the 20th day of March, in the year of our Lord 1833. One original is written in Siamese, the other in English; but as the Siamese are ignorant of English, and the Americans of Siamese, a Portuguese and a Chinese translation are annexed, to serve as testimony to the contents of the Treaty. The writing is of the same tenor and date in all the languages aforesaid. It is signed on the one part, with the name of the Chau Phaya-Phraklang, and sealed with the seal of the lotus flower, of glass. On the other part, it is signed with the name of Edmund Roberts, and sealed with a seal containing an eagle and stars.

One copy will be kept in Siam, and another will be taken by Edmund Roberts to the United States. If the Government of the United States shall ratify the said Treaty, and attach the Seal of the Government, then Siam will also ratify it on its part, and attach the Seal of its Government.

Article I

There shall be a perpetual Peace between the Magnificent King of Siam and the United States of America.

Article II

The Citizens of the United States shall have free liberty to enter all the Ports of the Kingdom of Siam, with their cargoes, of whatever kind the said cargoes may consist; and they shall have liberty to sell the same to any of the subjects of the King, or others who may wish to purchase the same, or to barter the same for any produce or manufacture of the Kingdom, or other articles that may be found there. No prices shall be fixed by the officers of the King on the articles to be sold by the merchants of the United States, or the merchandise they may wish to buy, but the Trade shall be free on both sides to sell, or buy, or exchange, on the terms and for the prices the owners may think fit. Whenever the said citizens of the United States shall be ready to depart, they shall be at liberty so to do, and the proper officers shall furnish them with Passports: Provided always, there be no legal impediment to the contrary. Nothing contained in this Article shall be understood as granting permission to import and sell munitions of war to any person excepting to the King, who, if he does not require, will not be bound to purchase them; neither is permission granted to import opium, which is contraband; or to export rice, which cannot be embarked as an article of commerce. These only are prohibited.

Article III

Vessels of the United States entering any Port within His Majesty’s dominions, and selling or purchasing cargoes of merchandise, shall pay in lieu of import and export duties, tonnage, licence to trade, or any other charge whatever, a measurement duty only, as follows: The measurement shall be made from side to side, in the middle of the vessel’s length; and, if a single-decked vessel, on such single deck; if otherwise, on the lower deck. On every vessel selling merchandise, the sum of 1700 Ticals, or Bats, shall be paid for every Siamese fathom in breadth, so measured, the said fathom being computed to contain 78 English or American inches, corresponding to 96 Siamese inches; but if the said vessel should come without merchandise, and purchase a cargo with specie only, she shall then pay the sum of 1,500 ticals, or bats, for each and every fathom before described. Furthermore, neither the aforesaid measurement duty, nor any other charge whatever, shall be paid by any vessel of the United States that enters a Siamese port for the purpose of refitting, or for refreshments, or to inquire the state of the market.

Article IV

If hereafter the Duties payable by foreign vessels be diminished in favour of any other nation, the same diminution shall be made in favour of the vessels of the United States.

Article V

If any vessel of the United States shall suffer shipwreck on any part of the Magnificent King’s dominions, the persons escaping from the wreck shall be taken care of and hospitably entertained at the expense of the King, until they shall find an opportunity to be returned to their country; and the property saved from such wreck shall be carefully preserved and restored to its owners; and the United States will repay all expenses incurred by His Majesty on account of such wreck.

Article VI

If any citizen of the United States, coming to Siam for the purpose of trade, shall contract debts to any individual of Siam, or if any individual of Siam shall contract debts to any citizen of the United States, the debtor shall be obliged to bring forward and sell all his goods to pay his debts therewith. When the product of such bona fide sale shall not suffice, he shall no longer be liable for the remainder, nor shall the creditor be able to retain him as a slave, imprison, flog, or otherwise punish him, to compel the payment of any balance remaining due, but shall leave him at perfect liberty.

Article VII

Merchants of the United States coming to trade in the Kingdom of Siam and wishing to rent houses therein, shall rent the King’s Factories, and pay the customary rent of the country. If the said merchants bring their goods on shore, the King’s officers shall take account thereof, but shall not levy any duty thereupon.

Article VIII

If any citizens of the United States, or their vessels, or other property, shall be taken by pirates and brought within the dominions of the Magnificent King, the persons shall be set at liberty, and the property restored to its owners.

Article IX

Merchants of the United States, trading in the Kingdom of Siam, shall respect and follow the laws and customs of the country in all points.

Article X

If thereafter any foreign nation other than the Portuguese shall request and obtain His Majesty’s consent to the appointment of Consuls to reside in Siam, the United States shall be at liberty to appoint Consuls to reside in Siam, equally with such other foreign nation.

Whereas, the undersigned, Edmund Roberts, a citizen of Portsmouth, in the State of New Hampshire, in the United States of America, being duly appointed as Envoy, by Letters Patent, under the Signature of the President and Seal of the United States of America, bearing date at the City of Washington, the 26th day of January, in the year of our Lord 1832, for negotiating and concluding a Treaty of Amity and Commerce between the United States of America and His Majesty, the King of Siam.

Now know ye, that I, Edmund Roberts, Envoy as aforesaid, do conclude the foregoing Treaty of Amity and Commerce, and every Article and Clause therein contained; reserving the same, nevertheless, for the final Ratification of the President of the United States of America, by and with the advice and consent of the Senate of the said United States.

Done at the Royal City of Sia-Yut’hia (commonly called Bangkok), on the 20th day of March, in the year of our Lord 1833, and of the Independence of the United States of America the 57th.

Edmund Roberts
Source: Library of Congress

Click here to view a PDF file of the Treaty of Amity and Commerce of 1833 (PDF 114 KB).

• Robert F. Godec – State of Residency: Virginia Title: Ambassador Extraordinary and Plenipotentiary Appointment: August 4, 2022 Presentation of Credentials: October 7, 2022
• Michael George DeSombre – State of Residency: Illinois Title: Ambassador Extraordinary and Plenipotentiary Appointment: January 9, 2020 Presentation of Credentials: October 25, 2020 Termination of Mission: Left post January 20, 2021
• Glyn T. Davies – State of Residency: Washington, D.C. Title: Ambassador Extraordinary and Plenipotentiary Appointment: August 5, 2015 Presentation of Credentials: September 22, 2015 Termination of Mission: Left post September 29, 2018
• Kristie A. Kenney – State of Residency: Washington, D.C. Title: Ambassador Extraordinary and Plenipotentiary Appointment: January 10, 2011 Presentation of Credentials: April 27, 2011 Termination of Mission: Left post November 6, 2014.
• Eric G. John – State of Residency: Indiana Title: Ambassador Extraordinary and Plenipotentiary Appointment: May 21, 2007 Presentation of Credentials: January 8, 2008 Termination of Mission: Left post December 4, 2010
• Ralph L. Boyce – State of Residency: Virginia Title: Ambassador Extraordinary and Plenipotentiary Appointment: July 2, 2004 Presentation of Credentials: March 9, 2005 Termination of Mission: Left post December 28, 2007
• Darryl N. Johnson -State of Residency: Washington Title: Ambassador Extraordinary and Plenipotentiary Appointment: November 26, 2001 Presentation of Credentials: March 29, 2002 Termination of Mission: Left post December 28, 2004
• Richard E. Hecklinger – State of Residency: Virginia Title: Ambassador Extraordinary and Plenipotentiary Appointment: December 1, 1998 Presentation of Credentials: March 9, 1999 Termination of Mission: Left post December 21, 2001
• William H. Itoh – State of Residency: New Mexico Title: Ambassador Extraordinary and Plenipotentiary Appointment: Dec 19, 1995 Presentation of Credentials: February 20, 1996 Termination of Mission: Left post February 1, 1999
• David Floyd Lambertson – State of Residency: Kansas Title: Ambassador Extraordinary and Plenipotentiary Appointment: July 22, 1991 Presentation of Credentials: September 24, 1991 Termination of Mission: Left post August 25, 1995
• Daniel Anthony O’Donohue – State of Residency: Virginia Title: Ambassador Extraordinary and Plenipotentiary Appointment: Jul 11, 1988 Presentation of Credentials: August 13, 1988 Termination of Mission: Left post August 10, 1991
• William Andreas Brown – State of Residency: New Hampshire Title: Ambassador Extraordinary and Plenipotentiary Appointment: June 6, 1985 Presentation of Credentials: July 5, 1985 Termination of Mission: Left post August 5, 1988
• John Gunther Dean – State of Residency: New York Title: Ambassador Extraordinary and Plenipotentiary Appointment: October 1, 1981 Presentation of Credentials: October 26, 1981 Termination of Mission: Left post June 6, 1985
• Morton I. Abramowitz – State of Residency: Massachusetts Title: Ambassador Extraordinary and Plenipotentiary Appointment: June 27, 1978 Presentation of Credentials: August 9, 1978 Termination of Mission: Left post July 31, 1981
• Charles S. Whitehouse – State of Residency: Virginia Title: Ambassador Extraordinary and Plenipotentiary Appointment: May 8, 1975 Presentation of Credentials: May 30, 1975 Termination of Mission: Left post June 19, 1978
• William R. Kintner – State of Residency: Pennsylvania Title: Ambassador Extraordinary and Plenipotentiary Appointment: September 28, 1973 Presentation of Credentials: November 29, 1973 Termination of Mission: Left post March 15, 1975
• Leonard Unger – State of Residency: Maryland Title: Ambassador Extraordinary and Plenipotentiary Appointment: August 11, 1967 Presentation of Credentials: October 4, 1967 Termination of Mission: Left post November 19, 1973
• Graham A. Martin – State of Residency: Florida Title: Ambassador Extraordinary and Plenipotentiary Appointment: September 10, 1963 Presentation of Credentials: November 7, 1963 Termination of Mission: Left post September 9, 1967
• Kenneth Todd Young – State of Residency: New York Title: Ambassador Extraordinary and Plenipotentiary Appointment: March 29, 1961 Presentation of Credentials: June 22, 1961 Termination of Mission: Left post August 19, 1963
• U. Alexis Johnson – State of Residency: California Title: Ambassador Extraordinary and Plenipotentiary Appointment: January 30, 1958 Presentation of Credentials: February 14, 1958 Termination of Mission: Left post April 10, 1961
• Max Waldo Bishop – State of Residency: Arkansas Title: Ambassador Extraordinary and Plenipotentiary Appointment: December 3, 1955 Presentation of Credentials: January 9, 1956 Termination of Mission: Left post January 6, 1958 Note: Commissioned during a recess of the Senate; recommissioned after confirmation on January 18, 1956.
• John E. Peurifoy – State of Residency: South Carolina Title: Ambassador Extraordinary and Plenipotentiary Appointment: September 15, 1954 Presentation of Credentials: December 3, 1954 Termination of Mission: Died near Hua Hin, August 12, 1955 Note: Commissioned during a recess of the Senate; recommissioned after confirmation on December 3, 1954.
• William J. Donovan – State of Residency: New York Title: Ambassador Extraordinary and Plenipotentiary Appointment: August 3, 1953 Presentation of Credentials: September 4, 1953 Termination of Mission: Left post August 21, 1954.
• Edwin F. Stanton – State of Residency: California Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: April 27, 1946 Presentation of Credentials: July 4, 1946 Termination of Mission: Promoted to Ambassador Extraordinary and Plenipotentiary Note: Commissioned to Siam.
• Charles W. Yost – State of Residency: New York Title: Charg้ d’Affaires Appointment: [see note] Presentation of Credentials: January 5, 1946 Termination of Mission: Superseded, July 4, 1946 Note: Not commissioned; letter of credence sent to Yost by telegram, October 16, 1945.
• Willys R. Peck – State of Residency: California Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: August 19, 1941 Presentation of Credentials: September 16, 1941 Termination of Mission: Japanese forces occupied Bangkok, December 8, 1941 Note: Thailand declared war on the United States January 25, 1942. Peck, having been interned, left post June 29, 1942.
• Hugh Gladney Grant – State of Residency: Alabama Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: April 3, 1940 Presentation of Credentials: August 20, 1940 Termination of Mission: Left post August 30, 1941
• Edwin L. Neville – State of Residency: Ohio Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: May 28, 1937 Presentation of Credentials: October 2, 1937 Termination of Mission: Left post May 1, 1940 Note: Commissioned to Siam.
• James Marion Baker – State of Residency: South Carolina Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: August 30, 1933 Presentation of Credentials: December 9, 1933 Termination of Mission: Left post May 2, 1936 Note: Commissioned during a recess of the Senate; recommissioned after confirmation on January 15, 1934. Commissioned to Siam.
• David E. Kaufman – State of Residency: Pennsylvania Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: June 12, 1930 Presentation of Credentials: December 9, 1930 Termination of Mission: Left post June 15, 1933 Note: Commissioned to Siam.
• Harold Orville MacKenzie – State of Residency: New Jersey Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: March 3, 1927 Presentation of Credentials: June 28, 1927 Termination of Mission: Left post March 29, 1930 Note: Commissioned to Siam.
• William E. Russell – State of Residency: District of Columbia Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: September 28, 1925 Presentation of Credentials: [January 9, 1926] Termination of Mission: Left post January 7, 1927 Note: Commissioned during a recess of the Senate; recommissioned after confirmation on December 17, 1925. Commissioned to Siam. Officially received on January 9, 1926.
• Edward E. Brodie – State of Residency: Oregon Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: October 8, 1921 Presentation of Credentials: January 31, 1922 Termination of Mission: Left post May 2, 1925 Note: Commissioned to Siam.
• George W. P. Hunt – State of Residency: Arizona Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: May 18, 1920 Presentation of Credentials: September 6, 1920 Termination of Mission: Left post October 1, 1921 Note: Commissioned to Siam.
• George Pratt Ingersoll – State of Residency: Connecticut Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: August 8, 1917 Presentation of Credentials: November 24, 1917 Termination of Mission: Left post June 23, 1918 Note: Commissioned to Siam.
• William H. Hornibrook – State of Residency: Oregon Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: February 12, 1915 Presentation of Credentials: May 31, 1915 Termination of Mission: Presented recall, October 24, 1916 Note: Commissioned to Siam.
• Fred W. Carpenter – State of Residency: California Title: Envoy Extraordinary and Minister Plenipotentiary Appointment: September 12, 1912 Presentation of Credentials: January 22, 1913 Termination of Mission: Left post November 16, 1913 Note: Commissioned during a recess of the Senate; recommissioned after confirmation on March 1, 1913. Commissioned to Siam.
• Hamilton King – State of Residency: Michigan Title: Minister Resident/Consul General Appointment: January 14, 1898 Presentation of Credentials: April 26, 1898 Termination of Mission: Promoted to Envoy Extraordinary and Minister Plenipotentiary Note: Commissioned to Siam.
• John Barrett – State of Residency: Oregon Title: Minister Resident/Consul General Appointment: February 14, 1894 Presentation of Credentials: November 15, 1894 Termination of Mission: Presented recall, April 26, 1898 Note: Commissioned to Siam.
• Sempronius H. Boyd – State of Residency: Missouri Title: Minister Resident/Consul General Appointment: October 1, 1890 Presentation of Credentials: January 17, 1891 Termination of Mission: Relinquished charge, June 13, 1892 Note: Commissioned to Siam.
• Jacob T. Child – State of Residency: Missouri Title: Minister Resident/Consul General Appointment: March 9, 1886 Presentation of Credentials: June 5, 1886 Termination of Mission: Presented recall, January 17, 1891 Note: Commissioned to Siam.

Interested in information about official states visits by American and Thai Heads of State and Heads of Government through the years? Visit the links below for more. (Available in English only.)

• Visits by U.S. Heads of States to Thailand
• Visits by U.S. Secretary of States to Thailand
• Visits by Thai Heads of States and Heads of Government to United States

Our story begins two centuries ago when an American sea captain entered the port of Bangkok and initiated a historic friendship between two nations.

However, over decades, the expeditions, treaties, and state visits that became the chapters of this shared history forged what today is an important and lasting relationship.

To commemorate 200 years of friendship, Great and Good Friends featured royal gifts from King Bhumibol Adulyadej and Queen Sirikit, King Prajadhipok, King Chulalongkorn, and King Mongkut. These gifts, many of which were being displayed in Thailand for the first time, embody the significant chapters from this history and tell a story of two worlds uniting on the basis of goodwill and understanding.

Great and Good Friends was exhibited at the Queen Sirikit Musuem of Textiles in 2018. You can explore the virtual exhibition via Google Arts & Culture platform at g.co/greatandgoodfriends

View the archived Great and Good Friends website here.

Download archived Great and Good Friends website in PDF format (86.2MB)

For more information, please visit https://th.usembassy.gov/our-relationship/greatandgoodfriends/