It was incorporated as a new county as part of a general reorganization of local government in December 1952.
Both of these were part of general reorganizations of South Korean local government.
It was established on July 31, 1991, as part of a general reorganization of the national police force.
Osan came to be called by its current name in 1914, at the time of a general reorganization of local governments under Japanese rule.
It was formed in 1952 from parts of Chonchon and Changgang, as part of a general reorganization of local government.
However, it was not constituted as Iseo-myeon until the general reorganization of local government under the Japanese occupation in 1914.
It was established in a general reorganization of local government in 1952.
On the general reorganization of the army he commanded the 31st infantry brigade.
Originally part of Huichon, it was created in 1952 as part of a general reorganization of local government.
The county was formed from parts of Kilchu and Myŏngch'ŏn in the 1950s, as part of a general reorganization of local government.