Cheonan was a relatively small town for much of the early half of the 20th century. As a transportation center, it was the site of an early engagement in the Korean War, the Battle of Cheonan. Then, in 1963 three municipal districts in the area that were growing in size were merged and promoted to the category of si, meaning city, by order of Law No 1176. Thus the City of Cheonan was born, comprising the populations of Cheonan-gun, Cheonan-eup and Hwanseong-myeon. Over the next two decades, the city grew in size by incorporating neighboring populations, including that of Byeongcheon-myeon in 1973. In 1975 the city renamed 10 branch offices to 10 dongs, representing the major administrative regions of the city. The city continued to expand, absorbing neighboring ri, myeon, and eup, including Pungse-myeon and Guryong-ri in the early 80s. Throughout this time, new neighborhoods to the southwest that were collectively known as Cheonan-gun, such as Ssangbong-dong, also grew in population, and in 1995 Cheonan-gun and Cheonan-si were merged into one large Cheonan-si. Larger dong that comprised the city were subsequently separated into smaller factions, such as Ssangbong-dong into Bongmyong-dong and Ssangyong, which itself was later separated into Ssangyong 1(il)-dong and Ssangyong 2(i)-dong (and then again into Ssangyong 2(i)-dong and Ssangyong 3-dong in 2003). In 2002 a city ordinance promoted the northern fringe village of Jiksan-myeon and the southern fringe village of Mokcheon-myeon into Jiksan-eup and Mokcheon-eup. This extended the boundaries of the city to a span of approximately 16 kilometers from north (at Jiksan) to south (at Mokcheon), and about 12 kilometers from Sunmoon University in the west to Mount Taejo on the eastern fringe. Including all of its administrative regions (see below), the city now covers a total area of 636.25 km2.