Syngman Rhee
On July 20, 1948, Rhee was elected president of the Republic of Korea in the South Korean presidential election, 1948 with 92.3% of the vote; the second candidate, Kim Gu, received 6.7% of the vote. On August 15, the Republic of Korea was formally established in South Korea and Rhee was inaugurated as the first President of the Republic of Korea. The next month, on September 9, the north also proclaimed statehood as the Democratic People's Republic of Korea. Rhee himself had been an independence activist, and his relations with the "chinilpa" Korean elites who had collaborated with the Japanese were, in the words of the South Korean historian Kyung Moon Hwang, often "contentious," but in the end an understanding was reached in which, in exchange for their support, Rhee would not purge the elites. In particular, the Koreans who had served in the colonial-era National Police, whom the Americans had retained after August 1945, were promised by Rhee that their jobs would not be threatened by him. Upon independence in 1948, 53% of South Korean police officers were men who had served in the National Police during the Japanese occupation.
Korean conflict
As a result, two antagonistic states emerged, with diametrically opposed political, economic, and social systems. In South Korea, a general election was held on May 10, 1948. The Republic of Korea (or ROK) was established with Syngman Rhee as President, and formally replaced the US military occupation on August 15. In North Korea, the Democratic People's Republic of Korea (or DPRK) was declared on September 9, with Kim Il-sung, as prime minister. Soviet occupation forces left the DPRK on December 10, 1948. US forces left the ROK the following year, though the US Korean Military Advisory Group remained to train the Republic of Korea Army. The new regimes even adopted different names for Korea: the North choosing "Choson", and the South "Hanguk".