Timeline of U.S.-South Korean Relations

The United States sent its first envoy to South Korea in 1883. The United States led the U.N. coalition that fought a war to defend Korea after North Korea invaded it in 1950. Korea and the United States first signed a mutual defense treaty in 1953 and have worked closely together ever since to provide security in the region and combat global threats.

Here is a brief timeline of U.S.-South Korean diplomatic history and cooperation since the mid-20th century.

Rear Adm. Robert W. Shufeldt, USN, 1883 circa photograph. NHHC Photograph Collection, NH 45385.

Commodore Robert Shufeldt plays the critical role of establishing a diplomatic presence in the Kingdom of Korea and in negotiating our first bilateral trade treaty in 1882.

Minister Foote, his wife Rose, and Naval Attaché George Foulk with Korean staff on the steps of the U.S. Legation Office in 1884. Several additions would later be made to expand this building, which was renovated in 2004. (Photo: National Anthropological Archives, Smithsonian Institution)

In 1883 Lucius Hardwood Foote serves as the first U.S. envoy to Korea and purchases the grounds where our Chief of Mission residence currently stands.

Horace Allen, who would eventually be appointed Minister of the U.S. Lega-tion, served as the Mission's first official physician. Dur-ing a violent coup against the Korean royal family in 1884, Allen guarded the residence with a gun that he only later realized did not work. (Photo: God, Mammon and the Japanese by Fred Harrington)

In 1884, Dr. Horace Newton Allen establishes Korea’s first western-style medical institution that would eventually become Severance Hospital.

Horace Grant Underwood arrives in Korea in 1885 and goes on to serve as President of the Joseon Christian College, the predecessor to Yonsei University.

South Korean troops at a mountain lookout post along the 38th parallel (© AP Images)

Following Japan’s surrender at the end of World War II, the Korean Peninsula is divided at the 38th parallel into two occupation zones.

South Korean President Syngman Rhee (right) and General Douglas MacArthur, supreme allied commander in Japan, at the inauguration of the new republic in August 1948 (© Charles Gorry/AP Images)

The parties do not realize their hopes for a unified Korea and instead establish two separate nations: the Republic of Korea in the south and the communist Democratic People’s Republic of Korea in the north.

U.S. Marines regained control of Seoul’s Kimpo airfield in September 1950, three months after the North Korean invasion. (© Max Desfor/AP Images)

North Korean forces invade the South Korea. Led by the United States, a 16-country U.N. coalition undertakes South Korea’s defense while China enters the war on North Korea’s side.

South Korean President Syngman Rhee (right), after signing the mutual defense treaty that he said would deter aggression and strengthen world security (© George Sweers/AP Images)

An armistice ends the fighting, but the parties do not sign a peace treaty. The United States and the South Korea sign their mutual defense treaty.

President Trump and South Korean President Moon Jae-in at the White House on June 30, 2017 (© Evan Vucci/AP Images)

The first Korea-U.S. Free Trade Agreement enters into force in 2012; six years later President Trump and President Moon Jae-in sign a landmark, revamped free trade deal.

President Trump and South Korean President Moon Jae-in clasp hands at the Blue House in Seoul on November 7, 2017. (© Andrew Harnik/AP Images)

President Trump pays the first state visit to Seoul by a U.S. president in 25 years.

U.S. Army and South Korean soldiers take positions during a live-fire exercise in 2015. (© Lee Jin-man/AP Images)

The two close allies coordinate their response to the North Korean nuclear threat and their efforts to achieve complete denuclearization of the Korean Peninsula.