The Korean War began with North Korean forces launching a pre-dawn raid over the 38th parallel into South Korea.

The Korean War was an armed conflict on the Korean Peninsula fought between North Korea and South Korea and their allies. North Korea was supported by China and the Soviet Union, while South Korea was supported by the United Nations Command (UNC) led by the United States. The conflict was one of the first major proxy wars of the Cold War. Fighting ended in 1953 with an armistice but no peace treaty, leading to the ongoing Korean conflict.

Following are circles of latitude between the 35th parallel north and the 40th parallel north: