Gyeongui Line (1904–1945)
Following Japan's defeat in the Pacific War and the subsequent partition of Korea, the Gyeongui Line was divided at the 38th parallel between North and South Korea. On 25 August 1945, the Soviet Army began operating trains on the line north of Sariwon, whilst trains in the south terminated at Gaeseong. In 1946, the railways in both North and South were nationalised, creating the Korean National Railroad in the South and the Korean State Railway in the North. After the Korean War, the Gyeongui Line was split into three sections. In the South, the Seoul–Jangdan section became the KNR's Gyeongui Line, retaining the same name; in the North, the Bongdong–Pyeongyang section became the P'yŏngbu Line, whilst the Pyeongyang–Sinuiju section became the P'yŏngŭi Line.
20th-century events
Two wars and a near-war in the 1950s became the focus for capitalist versus communist struggle. The first war was the Korean War, fought between People's Republic of China-backed North Korea and mainly United States-backed South Korea. The Korean Peninsula was a Japanese colony between 1910 and 1945, when Soviet and American troops invaded and divided it along the 38th parallel. A communist government controlled the territory north of the border and a capitalist one controlled the South, with both authorities considering the other one illegitimate and claiming sovereignty over the entire peninsula. North Korea's invasion of South Korea on June 25, 1950 led to United Nations intervention. General Douglas MacArthur led troops from the United States, Canada, Australia, Great Britain, and other countries in repulsing the Northern invasion. However, the war reached a stalemate after Chinese intervention pushed U.N. forces back, and an ended hostilities in July 1953, leaving the two Koreas divided and tense for the rest of the century.