Today, in the 21st century, Koreans make exclusive use of the Korean alphabet system when writing. However, even up until the beginning of the 20th century, Chinese characters were widely used in transcribing the Korean language. Koreans' alphabet usage has noticeably and drastically changed over the past hundred years--this stems from the standardization of the Korean alphabet.
Until the 19th century, the nation's official alphabet system was that of Chinese. King Sejong invented the Korean alphabet in the 15th century and, since then, it has been used in a wide range of mediums, including messages from the king to his people, letters, and the translation of literature written in Chinese. However, official documents were always written in Chinese characters.
Chinese characters originated from a need for the Chinese people to transcribe their words. Therefore, it was an incredibly difficult task for Koreans to have to restructure Korean words to the completely different grammar of the Chinese writing system. Although practical documents such as those for servants and contracts would make use of Idu (a form of inscription developed during the Silla dynasty that borrowed sounds and meanings from Chinese to transcribe Korean words), it, too, was only usable by those who were skilled at writing Chinese characters.
As a number of foreign powers approached Korea at the end of the 19th century, the suzerain relationship between Korea and China began to weaken. At the same time, as the Korean peoples' national consciousness surfaced from the modernization of the nation, there were changes in the peoples' views of the Korean and Chinese writing systems. More than a century ago, Koreans began to desire a unity between the official spoken and written languages. In 1894, King Gojong stated that "All royal orders are either to be written in the Korean alphabet, with versions translated into Chinese, or with a mixture of Korean and Chinese," re-designating the Korean alphabet that had been known as Eonmun (colloquial alphabet) to Gukmun (national alphabet). Gukmun signifies that it is a national alphabet, meaning that the modern-day Korean alphabet system was recognized as the official alphabet of Korea.
With this change at the end of the 19th century came the decline of the Chinese and Idu, along with the new arrival of the mixed Korean and Chinese character system as a new system for writing. The mixed system, which appeared at the end of the 19th century, is a method in which Chinese and Korean characters are used together in examples such as, "大韓民國은 우리나라이다." Before then, Korean documents only contained Korean characters that followed the Korean grammar system, while Chinese documents only contained Chinese characters that followed the Chinese grammar system--there was never a combination of the two. The advent of the mixed Korean and Chinese character system was not only the start of Hangeul as an official alphabet, but set a foundation for the development of the Korean alphabet's exclusivity as the nation's primary writing system.
Meanwhile, the recognition of a few learned people of Korean as an exclusive system was solidified in movements that began at the end of the 19th century. In 1896, the Dognipsinmun (The Independent), a newspaper written entirely in Korean, was published. Furthermore, schools and institutions that carried out modern education began to teach students using textbooks written exclusively in Korean. As exclusive Korean mediums of style entered the Korean press and education systems, the Korean alphabet was quickly becoming the official writing system for the masses in the nation.
At turn of the 20th century, there were many disputes in Korea as to whether or not it was more appropriate to use the mixed Korean and Chinese system or favor exclusive use of the Korean alphabet. As movements emerged for the exclusive use of the Korean alphabet following 1945, the end of the 20th century saw the standardization of the Korean system in writing. Exclusive use of the Korean alphabet was carried out by the Hankyoreh Sinmun (Hankyoreh Newspaper) in the 1990's, and as more Koreans showed positive response to this movement, it spread to other publications, as well. A mixed language writing system, centered on the Korean alphabet, was incorporated as a policy in the Korean Standardization Act in 2005.