History of Korea
After the end of WWII in 1945, the Allies divided the country into a northern area (protected by the Soviets) and a southern area protected (primarily by the United States). In 1948, when the powers failed to agree on the formation of a single government, this partition became the modern states of North and South Korea. The peninsula was divided at the 38th Parallel: the "Republic of Korea" was created in the south, with the backing of the US and Western Europe, and the "Democratic People's Republic of Korea" in the north, with the backing of the Soviets and the communist People's Republic of China. The new premier of North Korea, Kim il-Sung, launched the Korean War in 1950 in an attempt to reunify the country under Communist rule. After immense material and human destruction, the conflict ended with a cease-fire in 1953. The two nations officially remain at war because a peace treaty was never signed. In 1991, both states were accepted into the United Nations.
Public holidays in South Korea
These days celebrate events considered joyous to Korea. In the beginning, Independence Declaration Day (March 1) was first stipulated in 1946. After the establishment of the Government of the Republic of Korea in 1948, four major National Celebration Days (Independence Declaration Day, Constitution Day, Liberation Day, National Foundation Day) were provided by "The Law Concerning the National Celebration Days" (국경일에관한법률) in 1949. 
In 2005, Hangul Day became the 5th National Celebration day.