United States Army Coast Artillery Corps troops were first deployed to Argentia in January 1941, initially Battery A of the 57th Coast Artillery (Tractor Drawn) (TD) Regiment with two or possibly four mobile 155 mm guns, and Battery B of the 62nd Coast Artillery (Anti-aircraft) (AA) Regiment.
A command known as the Harbor Defenses of Argentia and St. John's was established at this time to coordinate US coast defence activities in Newfoundland, under the Newfoundland Base Command.
On 20 July 1941 the 155 mm gun battery was redesignated as Battery A, 53rd Coast Artillery (TD) Regiment, and on 1 August 1941 (some sources 1942) the AA battery was redesignated as Battery A, 421st CA (AA) Battalion (Separate).
After the US entered the war following the attack on Pearl Harbor on 7 December 1941, construction on two batteries (Batteries 281 and 282) of two 6-inch guns each began in January 1942 and was completed in October 1942.
These guns were on shielded long-range carriages with reinforced concrete and earth bunkers housing magazines and fire control equipment.
On 16 February 1942 the harbour defence units in Newfoundland were redesignated as components of the 24th Coast Artillery (Harbor Defense) (Composite) Regiment, the headquarters and two additional batteries of which arrived at Fort McAndrew from the US on 25 March 1942.
In April 1942 the AA defences were strengthened with the arrival of the 422nd CA Battalion (AA).

By the end of 1942 the coast defence gun batteries in the Argentia area were as follows:
In March 1943 the 24th CA Regiment was reduced to a battalion.
In December 1943-January 1944 elements of the unit returned to the US for inactivation.
In October 1944 the unit was reorganized, but was not fully inactivated until 8 September 1945.
The date the unit was transferred to the US for inactivation is unclear.
Postwar, circa 1946 the coast defence batteries were inactivated.
The 6-inch guns of Batteries 281 and 282 survive.
Battery 282's guns are still in place, and in 1993 Battery 281's guns were moved to Fort Columbia in Washington state, US.
United States Army Coast Artillery Corps troops were first deployed to Argentia in January 1941, initially Battery A of the 57th Coast Artillery (Tractor Drawn) (TD) Regiment with two or possibly four mobile 155 mm guns, and Battery B of the 62nd Coast Artillery (Anti-aircraft) (AA) Regiment. A command known as the Harbor Defenses of Argentia and St. John's was established at this time to coordinate US coast defence activities in Newfoundland, under the Newfoundland Base Command. On 20 July 1941 the 155 mm gun battery was redesignated as Battery A, 53rd Coast Artillery (TD) Regiment, and on 1 August 1941 (some sources 1942) the AA battery was redesignated as Battery A, 421st CA (AA) Battalion (Separate). After the US entered the war following the attack on Pearl Harbor on 7 December 1941, construction on two batteries (Batteries 281 and 282) of two 6-inch guns each began in January 1942 and was completed in October 1942. These guns were on shielded long-range carriages with reinforced concrete and earth bunkers housing magazines and fire control equipment. On 16 February 1942 the harbour defence units in Newfoundland were redesignated as components of the 24th Coast Artillery (Harbor Defense) (Composite) Regiment, the headquarters and two additional batteries of which arrived at Fort McAndrew from the US on 25 March 1942. In April 1942 the AA defences were strengthened with the arrival of the 422nd CA Battalion (AA).
By the end of 1942 the coast defence gun batteries in the Argentia area were as follows:
In March 1943 the 24th CA Regiment was reduced to a battalion. In December 1943-January 1944 elements of the unit returned to the US for inactivation. In October 1944 the unit was reorganized, but was not fully inactivated until 8 September 1945. The date the unit was transferred to the US for inactivation is unclear. Postwar, circa 1946 the coast defence batteries were inactivated. The 6-inch guns of Batteries 281 and 282 survive. Battery 282's guns are still in place, and in 1993 Battery 281's guns were moved to Fort Columbia in Washington state, US.
Naval Station Argentia