When the tracks of the Gulf, Colorado and Santa Fe Railroad were extended from Temple to Lampasas in the early 1880s, a switching station was installed near the midway point. The settlement that grew up around the site became the town of Killeen, named for Frank P. Killeen, a native of Ireland and a senior official of the rail company. The first train arrived on May 15, 1882, marking the beginning of the town.
Many early residents of Killeen came from the nearby pioneer communities of Sugar Loaf (6 mi. N) and Palo Alto (3.5 mi.NE). Town lots were sold by the GC & SF Railroad and one of the earliest structures built was a wooden community school which opened in the fall of 1882. By the following year Killeen was the site of two gristmills and a cotton gin. The town was incorporated in 1893 and W.E. Hudson was elected to serve as the first mayor.
In the early years of Killeen's development, the town was primarily an agricultural center for the production of cotton, grain, wool and cattle. In 1942 it became the home of Camp Hood, now Fort Hood. The federal installation's growth as a major military base has had a dramatic impact on the city, making it one of the fastest growing towns in Texas.