Killeen is a city in Bell County, Texas, United States. According to the 2010 census, its population was 127,921, making it the 21st-most populous city in Texas and the largest of the three principal cities of Bell County. It is the principal city of the Killeen–Temple–Fort Hood Metropolitan Statistical Area. Killeen is 154.3 miles (248.3 km) southwest of Dallas, and 146 miles (235 km) northeast of San Antonio.
Killeen is directly adjacent to the main cantonment of Fort Hood. Its economy depends on the activities of the post, and the soldiers and their families stationed there. It is known as a military "boom town" because of its rapid growth and high influx of soldiers.
A fort existed at Killeen by 1862 at the very latest. The discovery of a surviving Confederate metal breast plate (2.5” high and 2.25” wide) confirms it.
On the front of the silvery-grey breast plate is a bold, impressed “TEXAS” at its top, above an attached three-dimensional circular horn/bugle with a raised 5-point star in its center, very nicely molded.