evidence: South Korea is an East Asian nation of some 51 million people located on the southern portion of the Korean Peninsula, which borders the East Sea (Sea of Japan) and the Yellow Sea. The United States and Soviet Union divided control over the peninsula after World War II, and in 1948 the U.S.-supported Republic of Korea (or South Korea) was established in the capital city of Seoul. Around A.D. 668, several competing kingdoms were unified into a single dominion on the Korean Peninsula. Successive regimes maintained Korean political and cultural independence for more than a thousand years; the last of these ruling kingdoms would be the Choson Dynasty (1392-1910). [...] Today, South Korea is one of East Asia’s most affluent countries, with an economy ranking just behind Japan and China. With most of the country covered by mountains, a majority of its population is clustered around the urban centers.