United Defense [SEP] inception
added aircraft and tanks to its growing munitions capability, further adding to the firm's diversified economic success and defense specialization.
Following a massive decline in orders for tracked combat vehicles between 1983 and 1994 FMC and the Harsco Corporation agreed in January 1994 to combine their defense businesses to form United Defense. The new company owned the former FMC California-based Ground Systems Division and Harsco's Pennsylvania-based BMY Combat Systems Division. The new company restructured its operations to concentrate final assembly and testing to Pennsylvania. 
In September 2000
CA Battalion (HD) (Sep). Battery K became Battery K (searchlight) HD Galveston. Batteries D and E were deactivated with personnel reassigned to HD Galveston, and the regiment was disbanded.
- 20th CA Battalion disbanded 31 March 1945 at Fort Travis.
See also.
- Coats of arms of U.S. Air Defense Artillery Regiments
- Distinctive unit insignia (U.S. Army)
- Seacoast defense in the United States
- United States Army Coast Artillery Corps
- Harbor Defense Command
References.