Pursuant to a United Nations resolution, general elections were held on May 10, 1948, in the southern half of the peninsula (North Korea refused UN supervised elections). A constituent national assembly was formed through the elections and the constitution was framed based on democratic principles. The National Assembly then elected Dr. Syngman Rhee as the first president of the republic. He formed the government and promulgated the birth of the Republic of Korea on August 15, 1948, after three years of U.S. military government. http://www.un.int/korea/index.htm