June 27, 1950 — Only two days before, thousands of North Korean soldiers had crossed into the South Korea, under the cover of artillery barrages over the 38th parallel. They were already on their way to Seoul by the 27th, and the world was watching closely. On this day in history, U.S. President Harry Truman ordered military forces to aid the South Korea in the fight against the north. This was in line with the U.N. Security Council’s Resolution 82, which supported military action from U.N. member states in South Korea.

American involvement in the war was also closely tied to the fight against communism. On top of the dangers of communism in general, at the time the rapid spread of communism looked a whole lot like the rapid spread of Nazism that, only one decade prior, had the entire world engulfed in the most devastating war in history. The same president was still in office, the same officials and military service members who literally fought in WWII were still undoubtedly reeling from the war. Though with the U.N.’s support and South Korea’s need for assistance, they didn’t need any other reason, but this was still undoubtedly a contributing factor.

As American troops began to flood into the country, the U.S. saw their first major battle in Osan, just south of Seoul, on 5 July, 1950. The war would continue on for three more years, claiming the lives of hundreds of thousands of combatants, including almost 34,000 American troops from hostile engagements, and over 100,000 wounded in action. South Korea suffered approximately 217,000 deaths, and over a million civilians lost; North Korea lost over 400,000 troops, and suffered approximately 600,000 civilian deaths.

According to the Defense POW/MIA Accounting Agency, there are still 7,697 U.S. military personnel unaccounted for from the Korean War. In recent developments, the United States has been promised the return of the remains of 200-250 service members that have been listed as MIA from the Korean War, as the relationship between Kim Jong Un and President Donald Trump is rapidly changing.