| 21st Coast Artillery Regiment | |
|---|---|
| Active | 1940–1944 |
| Country |  United States |
| Branch | Army |
| Type | Coast artillery |
| Role | Harbor defense |
| Size | Regiment |
| Part of | Harbor Defenses of the Delaware |
| Garrison/HQ | |
| Mascot(s) | Oozlefinch |
The 21st Coast Artillery Regiment was a regiment of the United States Army Coast Artillery Corps. It was the regular army component of the Harbor Defenses of the Delaware in World War II. The 21st CA (Harbor Defense) (HD) Regiment was active from February 1940 until broken up in October 1944 as part of an Army-wide reorganization.[1]
- ^ Stanton, p. 459