North and South Korea once again divided near the 38th parallel: the war ended with an armistice, an agreement to end fighting, leaving the country essential split in the exact place it started.
In an effort to reunited Korea, the North attacked the South in 1949. The UN and US troops came in to defend against the Northern attack. China entered the war tipping the war back to a balanced state, creating a stalemate. The end result was an agreement to end the fighting and redivide Korea into North and South.