Wars on Map

Korea, 1950–1953

Korean War Map & Timeline: 1950–1953

No front in modern history moved as far, as fast, in both directions as the Korean front did between June 1950 and June 1951. It ran the length of the peninsula twice in twelve months — and then, for two more years, barely moved at all while the negotiations ground on and the casualties kept accumulating. That shape is the whole war, and it is the kind of thing only a map shows.

Sources checked 2026-09-11 · Estimates are given as ranges, not single figures

4Times Seoul changed hands: June 1950, September 1950, January 1951 and March 1951.
2.5–3.5mDeaths on all sides including civilians, who were the majority.
1953Year of the armistice. There has never been a peace treaty.

A war in three distinct phases

The first phase was a North Korean offensive that nearly ended the war outright. The Korean People’s Army crossed the 38th parallel before dawn on 25 June 1950, took Seoul in three days, and pushed the South Korean and arriving American forces into a perimeter around Pusan in the southeastern corner of the peninsula by early August.

The second phase reversed it completely. The amphibious landing at Inchon on 15 September cut the North Korean supply lines behind the front; Seoul was retaken within a fortnight, Pyongyang in October, and United Nations forces reached parts of the Yalu river on the Chinese border in November. Then Chinese forces, which had begun crossing in late October, attacked in strength and drove the front back south of Seoul by January 1951.

The third phase was a stalemate along a line close to the original border. From the summer of 1951 the fighting was for hills and outposts — Heartbreak Ridge, Triangle Hill, Pork Chop Hill — while armistice talks ran at Kaesong and then Panmunjom for two years. Roughly half of all American deaths in the war occurred during this period, when the map had stopped changing.

Sources
Millett, A. R. (2010), The War for Korea, 1950–1951: They Came from the North. University Press of KansasHastings, M. (1987), The Korean War. Michael JosephCumings, B. (2010), The Korean War: A History. Modern Library

Timeline of the Korean War

The catalogue codes the war’s start as 24 June 1950 and its end as the armistice of 27 July 1953. The start date is the attack in Universal Time: in Korea it was already the small hours of 25 June.

  1. 25 June 1950North Korea invades the South

    The attack crosses the 38th parallel before dawn. The UN Security Council, which the Soviet Union was boycotting, calls for a withdrawal the same day and for military assistance to South Korea on 27 June.

  2. 28 June 1950Seoul falls

    South Korean forces lose most of their equipment in the retreat south.

  3. 5 July 1950First American ground action at Osan

    A single under-strength battalion is overrun, setting the pattern for the first weeks of piecemeal commitment.

  4. August – September 1950The Pusan Perimeter holds

    A shrinking bridgehead in the southeast is held against repeated attacks while reinforcements and air power build up.

  5. 15 September 1950Landing at Inchon

    Operation Chromite lands behind the North Korean front on a tidal coast that most planners considered unusable. Seoul is recaptured by 28 September.

  6. 1–7 October 1950UN forces cross the 38th parallel

    The war’s aim changes from restoring the border to unifying the peninsula — the decision that brings China in.

  7. 19 October 1950Pyongyang is taken; Chinese forces begin crossing the Yalu

    The crossings are undetected. The first Chinese offensive follows on 25 October, and a much heavier one on 25 November.

  8. 27 November – 13 December 1950Chosin Reservoir

    Encircled American and allied units fight south through mountain passes in extreme cold to the port of Hungnam, from which the northeast is evacuated.

  9. 4 January 1951Seoul falls for the third time

    The UN line is pushed some 80 kilometres south of the capital before it holds.

  10. 14 March 1951Seoul is retaken for the last time

    Counter-offensives through the spring return the front to roughly the 38th parallel, where it stays.

  11. 11 April 1951MacArthur is relieved of command

    The dispute is over whether to widen the war into China. The decision to keep it limited holds.

  12. 10 July 1951Armistice talks open at Kaesong

    They move to Panmunjom in October and continue for two years, deadlocked largely over the repatriation of prisoners.

  13. 1951–1953The war of the outposts

    Fighting for hills along a fortified line: Bloody Ridge and Heartbreak Ridge in 1951, Triangle Hill in 1952, Pork Chop Hill in 1953.

  14. 27 July 1953The armistice is signed

    It creates a demilitarised zone about four kilometres wide along the front. South Korea does not sign it, and no peace treaty has ever followed.

Sources
Millett, A. R. (2010), The War for Korea, 1950–1951: They Came from the North. University Press of KansasHastings, M. (1987), The Korean War. Michael JosephCorrelates of War — war datasets and codebooks ↗

Korean War casualties

The figures for the United Nations side are among the best-documented of any twentieth-century war. Those for North Korea, China and the civilian population are not, and the total depends almost entirely on estimates for the last of those.

PartyDeathsBasis
United States36,574 total, about 33,700 in battleDepartment of Defense casualty accounting
South Korea, militaryAbout 138,000South Korean Ministry of National Defense figures
Other UN contingentsAbout 3,400Sixteen countries sent combat forces; the United Kingdom and Turkey lost the most
ChinaAbout 197,700Official Chinese figure published in 2010; earlier and higher Western estimates remain in circulation
North Korea, military215,000 – 400,000No archival release; all figures are estimates
Korean civilians, both sides1.5 – 3 millionThe great majority of deaths in the war, from ground fighting, bombing, famine and reprisals

The civilian range is the reason the war’s total is quoted anywhere between 2.5 and 4.5 million. No reconstruction of North Korean civilian mortality has ever been possible.

Sources
U.S. Department of Defense, Defense Casualty Analysis System — Korean War and Vietnam War casualty summariesMillett, A. R. (2010), The War for Korea, 1950–1951: They Came from the North. University Press of KansasCumings, B. (2010), The Korean War: A History. Modern LibraryClodfelter, M. (2017), Warfare and Armed Conflicts: A Statistical Encyclopedia, 4th ed. McFarland

What the catalogue shows, and one artefact to know about

The catalogue codes Korea as an inter-state war with sixteen participants and twelve separate combat periods, one for each country as it entered. That structure is visible in the evidence panel and is genuinely useful: you can see the war assembling itself between June 1950 and the end of 1951.

The map marker for this record, however, is an artefact. The atlas places wars by averaging the modern country centroids of the participants it can resolve, and for this record that average falls in northern China, not in Korea. The panel says as much wherever a position is derived this way. For this war the timeline is trustworthy and the single marker is not.

Sources
Correlates of War — war datasets and codebooks ↗Sarkees, M. R. & Wayman, F. W. (2010), Resort to War: 1816–2007. CQ Press

Open the atlas at September 1950 — the Pusan Perimeter and the Inchon landing ↗