The Heroína, a privately owned frigate that is operated as a privateer under a license issued by the United Provinces of the River Plate, under the command of American Colonel David Jewett, in March 1820 sets sail looking to capture Spanish ships as prizes.

Most of her crew after seven months are incapacitated by scurvy and disease.

Jewett executes six of his crew for an attempted mutiny.

He is unable to find any Spanish prizes but does manage to capture a Portuguese ship named Carlota.

Jewett is considered to have committed piracy, as Argentina and Portugal are not at war.

A storm results in severe damage to the Heroína and sinks the prize Carlota, forcing Jewett to put into Puerto Soledad for repairs in October 1820.

Captain Jewett chooses to rest and recover in the islands, seeking assistance from the British explorer James Weddell.

Weddell reported only thirty seamen and forty soldiers fit for duty out of a crew of two hundred, and that Jewett slept with pistols over his head following the mutiny.

Jewett raises the flag of the United Provinces of the River Plate (a predecessor of modern-day Argentina) on November 6, 1820, and claims possession of the islands.

Weddell does not believe that Jewett is acting with the interests of the United Provinces of the River Plate in mind; rather, Jewett had merely put into the harbor in order to obtain refreshments for his crew, and that the assumption of possession was chiefly intended for the purpose of securing an exclusive claim to the wreck of the French ship Uranie that had foundered at the entrance of Berkeley Sound a few months prior.

Weddell leaves the islands on November 20, 1820, noting that Jewett had not completed repairs to the Heroína.

Jewett finally seizes an American flagged ship named Rampart, committing piracy for a second time.

Jewett sends a long report to Buenos Aires dated February 1, 1821, in which he describes his journey.

He does not, however, make any mention of his claim over the Falklands.

News of Jewett's claim over the Falklands is reported first in the Salem Gazette, a Massachusetts news paper, and reprinted in the Times of London.

The Spanish newspaper Cadiz then reports the story and it is only when this report reaches Buenos Aires, as a foreign news story, that its is published in the Buenos Aires Argos on November 10, 1821, more than a year after the event.

The Argentine government itself makes no announcements.

This is probably because Jewett had made no report of his 'acquisition', so the authorities are completely unaware that it had taken place.

Jewett had departed from the Falkland Islands in April 1821, having spent no more than six months on the island, entirely at Puerto Soledad.

Jewett in 1822 is accused of piracy by a Portuguese court, but by this time he is in Brazil.