In the morning calm of June 25, 1950, an well-armed Communist North Korean Army with a military of seven divisions and one armored division crossed the 38th Parallel and invaded the Republic of South Korea. Trained and equipped by the Russians this North Korean Army had little resistance from the surprised Allied occupying force. By 23 July 1950 the heavily outnumbered UN forces were pushed back toward Pusan and the North Korean Army had now taken all but about 150 miles of South Korea. The Security Council of the United Nations immediately denounced this breach of the Potsdam agreement. Supporting the decision of that body, the United States came to the defense of South Korea, first sending in what had been Army occupation troops in Japan, and then calling on U.S. Marines, which at that time had only about 80,000 on active duty.
This crossing was in violation of the Potsdam agreement made 26 July 1945, by the United States, the United Kingdom, and the Republic of China. Later on 27 December 1945 in Moscow, the Soviet Government reaffirmed this agreement. At the Moscow meeting the Soviets agreed that a provisional democratic government should be established to take the place of the Japanese occupation for all of Korea until the Koreans themselves could permanently organize an independent and united country. Unfortunately the country was divided at the 38th parallel, the Soviet Government occupying North Korea, UN Allied forces occupying South Korea.
Under the leadership of General Douglas MacArthur as Supreme Commander of the Allied UN forces October 1950 had taken all of Korea, north and south. The Communist North Korean Army was annihilated. The Russians abandoned North Korea and Mao Tse Tung sent Chinese "Volunteers" to "resist the attacks of U.S. Imperialism and the carnage continued until July 27,1953 when the armistice was sighed at Panmunjom.*
In order to take back the occupied territory, General Douglas MacArthur put in a plan to invade from the sea. The first obstacles to over come, were to remove the Russian mines now moored along the Korea coastline. Here the minefield needed to be swept for the invasion, to deceive and confuse the enemy as to where the invasion would be.

During this operation five US ships were lost and one Republic of Korea (ROK) YMS minesweeper.**


Ship Name

Date Sunk



AMS-25, USS Magpie

29 September 1950



AM-275 USS Pirate

12 October 1950



AM-277 USS Pledge

12 October 1950



AMS-31 Patridge

02 February 1951



ATF-111 USS Sari

27 August 1952




October 1950


U. S. Navy Casualties in the Korean War


Killed in action


Died of Wounds


Missing in action and known or presumed dead




Wounded in action


Total U. S Ships Lost or Damaged

*See "The Korean War by Max Hastings, Simon & Schuster, Copyright 1987, Romadata Ltd.

**Also see "The Sea War in Korea" By Malcolm W. Cagle, Commander, U. S. Navy and Frank A. Manson, Commander, U. S. Navy, Annapolis, Maryland United States Naval Institute, ARNO Press, New York, 1980 for in-depth account of the conflict. Although this is a good record of the war at the beginning the hostilities efforts of the replacements minesweepers are missing.