75 years ago today, on July 13, 1950 (May 29, 1950 lunar calendar), the Northeast Border Guard was formed. On July 13, 1950, the Northeast Border Guard of the Chinese People's Liberation Army was formed. On June 25, the Korean Civil War broke out. On the 26th, US President Truman ordered General MacArthur, the commander-in-chief of the US Far East Army, to "provide naval and air support to South Korea" and to intervene in the internal affairs of North Korea. On the 27th, US President Truman issued another statement announcing that the US government decided to prevent the Chinese government from liberating Taiwan by force. On July 7, the US manipulated the UN Security Council to pass an illegal resolution and formed the so-called "United Nations Army" with the US army as the main force to expand the war of aggression. In this case, the Central Military Commission decided to form the Northeast Border Guard Force with the original 13th Corps of the Fourth Field Army as the main unit. Su Yu was the commander and political commissar, and it had jurisdiction over 4 corps, 3 artillery divisions, 1 anti-aircraft artillery regiment, and 1 engineer regiment. A total of about 225,000 people were stationed in Fengcheng, Liaoyang, Andong (now Dandong), Tonghua, Benxi and other places to undertake the task of safeguarding the security of the Northeast Border Guard. In October, according to the order of Mao Zedong, Chairperson of the Military Commission of the Chinese People's Revolution, the Northeast Border Guard was changed to the Chinese People's Volunteer Army and went to Korea to participate in the war.