The 4th Air Defense Artillery Regiment was constituted 1 June 1821 in the Regular Army as the 4th Regiment of Artillery and organized from new and existing units with headquarters at Pensacola, Florida. As a result of the division of the Artillery Corps into Coast and Field Artillery units, the Regiment was broken up 13 February 1901, and its elements reorganized and redesignated as separate numbered companies and batteries of the Artillery Corps.
The 11th Coast Artillery was a coast artillery regiment in the United States Army, first constituted in the Regular Army on 27 February 1924. It primarily served as the Regular Army component of the Harbor Defenses of Long Island Sound, New York from 1924 through 1944, when it was relieved and disbanded as part of an Army-wide reorganization.
The 3rd Air Defense Artillery Regiment is an air defense artillery regiment of the United States Army, first formed in 1821 as the 3rd Regiment of Artillery.
The 7th Air Defense Artillery Regiment is an air defense artillery regiment of the United States Army, first constituted in the Regular Army as the 7th Regiment of Artillery on 8 March 1898. The 6th and 7th U.S. Artillery Regiments were constituted on 8 March 1898, three weeks after the explosion of USS Maine in Havana, Cuba on 15 February 1898, as the United States' declaration of war on Spain and commencement of the Spanish–American War seemed imminent.
The 6th Air Defense Artillery Regiment is an air defense artillery regiment in the United States Army, first formed in 1898 as the 6th Regiment of Artillery. The 6th and 7th U.S. Artillery Regiments were constituted on 8 March 1898, three weeks after the explosion of the USS Maine in Havana, Cuba on 15 February 1898, as the United States' declaration of war on Spain and commencement of the Spanish–American War seemed imminent.
The 8th Coast Artillery Regiment was a Coast Artillery Corps regiment in the United States Army, which garrisoned the Harbor Defenses of Portland, Maine 1924–1944, and the Harbor Defenses of Portsmouth, New Hampshire 1924–1940.
The 9th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army.
The 10th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army. It primarily served as the Regular Army coast artillery component of the Harbor Defenses (HD) of Narragansett Bay, Rhode Island from 1924 through 1944, when it was relieved and disbanded as part of an Army-wide reorganization.
The 13th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army. Elements of the regiment served during World War II in the Harbor Defenses of Pensacola, HD Key West, HD Galveston, HD Charleston, Temporary HD of New Orleans, and in Bora Bora in the South Pacific. The regiment was broken up and its elements redesignated on 31 August 1944 as part of an Army-wide reorganization.
The 14th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army. It served as the Regular Army component of the Harbor Defenses (HD) of Puget Sound, Washington state from 1924 through October 1944, when it was broken up and disbanded as part of an Army-wide reorganization. The 248th Coast Artillery Regiment was the Washington National Guard component of those defenses.
The 15th Coast Artillery was a Coast Artillery Corps regiment in the United States Army. Along with the 16th Coast Artillery, it manned the Harbor Defenses of Pearl Harbor and other fortified sites on Oahu, Hawaii from 1924 until broken up into battalions in August 1944 as part of an Army-wide reorganization.
The 16th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army, along with the 15th Coast Artillery, it manned the Harbor Defenses of Honolulu and other fortified sites on Oahu, Hawaii from 1924 until broken up into battalions in August 1944 as part of an Army-wide reorganization. The regiment manned many gun batteries at locations all over Oahu. Most of the forts where they were assigned were originally built 1899–1910, and had been in caretaker status for more than 30 years. On the morning of 7 December 1941, the soldiers of the 16th Coast Artillery manned their anti-aircraft guns, bringing down six of the attacking Japanese aircraft.
The 18th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army. It was the Regular Army component of the Harbor Defenses of the Columbia, replacing the 3rd Coast Artillery there. Other elements of the regiment were also part of the Harbor Defenses of San Francisco. The regiment was active from 1940 until withdrawn in April 1944 and inactivated the following month as part of an Army-wide reorganization.
The 20th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army. It was the garrison of the Harbor Defenses of Galveston in World War II, with Battery C deployed to Tongatapu, Tonga March-August 1942. Until the 20th CA (HD) was fully activated in April 1942, HD Galveston was also garrisoned by the 265th Coast Artillery (HD) Regiment and elements of the 50th Coast Artillery (TD) Regiment. The 20th CA Regiment was active from August 1940 until broken up and partly deactivated in August 1944 as part of an Army-wide reorganization.
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 (HD) Regiment was active from February 1940 until broken up in October 1944 as part of an Army-wide reorganization.
The 22nd Coast Artillery Regiment was a Coast Artillery regiment in the United States Army. It was the garrison of the Harbor Defenses of Portsmouth in World War II. The 22nd CA (HD) Regiment was active from February 1940 until broken up in March 1944 as part of an Army-wide reorganization.
The 23rd Coast Artillery Regiment was a Coast Artillery Corps regiment in the United States Army. It was the garrison of the Harbor Defenses of New Bedford, Massachusetts in World War II, as a battalion in February 1940 through expansion to a regiment in September 1943, then reduced to a battalion in February 1944 until inactivated in October 1944.
The 24th Coast Artillery Regiment was a Coast Artillery regiment in the United States Army. It was the garrison of the Harbor Defenses of Argentia and St. John's, Newfoundland from February 1942 through October 1944, as a battalion after March 1943.
The 50th Coast Artillery Regiment was a Coast Artillery Corps regiment in the Regular Army. It was mobilized in World War I and World War II.
The 249th Coast Artillery Regiment was a Coast Artillery Corps regiment in the Oregon National Guard. It garrisoned the Harbor Defenses of the Columbia, Oregon and Washington 1924–1944.
United States