U.S. military administration 1945–1948
announced the surrender of the
Empire of Japan to the
Allied Powers on 15 August 1945.
General Order No. 1 for the surrender of Japan (prepared by the Joint Chiefs of Staff of U.S. military forces and approved on 17 August 1945) prescribed separate surrender procedures for Japanese forces in Korea north and south of the 38th parallel. After
Japan's surrender to the Allies (formalised on 2 September 1945), division at the
38th parallel marked the beginning of Soviet and U.S. trusteeship over the North and South, respectively. This division was meant to be temporary and was first intended to return a unified Korea back to its people until the United States,
Soviet Union, and
Republic of China could arrange a trusteeship administration. In February 1945 the
Yalta Conference discussed the issue of trusteeship for Korea.
 U.S. forces landed at
Incheon on September 8, 1945 and established a military government shortly thereafter.
 Lt. General
John R. Hodge, their commander, took charge of the government.
 Faced with mounting popular discontent, in October 1945 Hodge established the Korean Advisory Council. A year later, an interim legislature and interim government were established, headed by
Kim Kyu-shik and
Syngman Rhee respectively. However, these interim bodies lacked any independent authority or
de jure sovereignty, which was still held by the
Provisional Government of the Republic of Korea based in China, but U.S. leaders chose to ignore its legitimacy, partly because of it communist alignment.
 Political and economic chaos - arising from a variety of causes - plagued the country in this period. The after-effects of the Japanese exploitation remained in the South, as in the North.
 In addition, the U.S. military was largely unprepared for the challenge of administering the country, arriving with no knowledge of the language, culture or political situation.
 Thus many of their policies had unintended destabilizing effects. Waves of refugees from North Korea and returnees from abroad added to the turmoil.
In December 1945 a conference convened in
Moscow to discuss the future of Korea.
 A 5-year trusteeship was discussed, and a US-Soviet joint commission was established. The commission met intermittently in
Seoul but deadlocked over the issue of establishing a national government. In September 1947, with no solution in sight, the
United States submitted the Korean question to the
UN General Assembly.
The resolution from the UN General Assembly called for a UN-supervised general election in Korea, but after the North rejected this proposition, a general election for a Constitutional Assembly took place in the South only, in May 1948. A constitution was adopted, setting forth a presidential form of government and specifying a four-year term for the presidency. According to the provisions of the Constitution, an indirect presidential election took place in July. Syngman Rhee, as head of the new assembly, assumed the presidency and proclaimed the
Republic of Korea (South Korea) on August 15, 1948.