World War II divided Korea into a Communist, northern half and an American-occupied southern half, divided at the 38th parallel. The Korean War (1950-1953) began when the North Korean Communist army crossed the 38th Parallel and invaded non-Communist South Korea. This Chinese army attacked the US/UN/ROK forces.
The United Nations, with the United States as the principal participant, joined the war on the side of the South Koreans, and the People's Republic of China came to North Korea's aid.
After three years of a bloody and frustrating war, the United States, the People's Republic of China, North Korea, and South Korea agree to an armistice, bringing the fighting of the Korean War to an end. The armistice ended America's first experiment with the Cold War concept of “limited war.”
