She was originally the American privateer brig Thorn, Asa Hooper master, and was armed with eighteen long 9-pounder guns.

[2][a] At the time of her capture she had already taken as prizes the brig Freedom, loaded with salt, and the American vessel Hiram, with a cargo of flour and bread on a voyage to Lisbon and traveling with a British license (safe conduct pass) that asked all British naval vessels and privateers to let her pass, provided that she was on a bona fide passage to Spain or Portugal with flour.

Sir John Sherbrooke's primary captain was Joseph Freeman, an experienced privateer officer from Liverpool, Nova Scotia, who was a veteran who did everything in navy fashion.

Sir John Sherbrooke had gathered 50 Irish labourers when on 26 May 1813 she recaptured Duck, which was transporting them from Waterford to Newfoundland.

Sir John Sherbrooke also began the chase of the notorious American privateer schooner Young Teazer, which British naval ships, including Hogue and Orpheus then took up.

Far larger than most colonial privateers, Sir John Sherbrooke required a constant supply of American captures to pay for her large crew.

Following the destruction of most American shipping during the war, Sir John Sherbrooke became unprofitable to operate as a privateer and her owners sold her in 1814.

Lloyd's List (LL) reported on 21 October 1814 that Sir John Sherbrooke, Lester, master, was one of four merchantmen that American privateers had captured.

Salvage was impracticable, so the cutting-out party from the frigate set Sir John Sherbrooke on fire; she then burned to the water's edge.

On 16 November 1814, boats from HMS Spencer and Telegraph, herself a former American privateer, ran Syren ashore under Cape May, where her crew destroyed her.