Jemmy Button was a boy of about 14 from Tierra del Fuego who was taken to England in 1828, on board the Beagle, a British sailing ship. On Darwin's later voyage on the Beagle, Jemmy Button and two fellow Fuegians, Fuegia Basket and York Minster, were being returned to their homeland. A fourth companion, Boat Memory, had died in England.

Fitzroy's idea was to civilize a few Indians, who would return and Christianize their tribes, ensuring a safe place for sailing ships and whalers to stop for provisions and repairs.

On December 17, 1832, Jemmy Button and the others were put ashore on Tierra del Fuego with a cargo of clothing, seeds, and agricultural tools. They had largely forgotten their native language. A few months later the ship contacted Jemmy and offered to take him back to England; he refused. The civilizing mission was a failure; aside from speaking some English, the three completely reverted to their native culture.

In 1859 Jemmy Button led an attack that killed several British missionaries from the Falkland Islands.

Below is Darwin's description of Jemmy Button:
Jemmy Button was a universal favourite, but likewise passionate; the expression of his face at once showed his nice disposition. He was merry and often laughed, and was remarkably sympathetic with any one in pain: when the water was rough, I was often a little sea-sick, and he used to come to me and say in a plaintive voice, "Poor, poor fellow!" but the notion, after his aquatic life, of a man being sea-sick, was too ludicrous, and he was generally obliged to turn on one side to hide a smile or laugh, and then he would repeat his "Poor, poor fellow!" He was of a patriotic disposition; and he liked to praise his own tribe and country, in which he truly said there were "plenty of trees," and he abused all the other tribes: he stoutly declared that there was no Devil in his land. Jemmy was short, thick, and fat, but vain of his personal appearance; he used always to wear gloves, his hair was neatly cut, and he was distressed if his well-polished shoes were dirtied. He was fond of admiring himself in a looking glass; and a merry-faced little Indian boy from the Rio Negro, whom we had for some months on board, soon perceived this, and used to mock him: Jemmy, who was always rather jealous of the attention paid to this little boy, did not at all like this, and used to say, with rather a contemptuous twist of his head, "Too much skylark." It seems yet wonderful to me, when I think over all his many good qualities that he should have been of the same race, and doubtless partaken of the same character, with the miserable, degraded savages whom we first met here.

There is a fictionalized biography of Jemmy Button, Tierra del Fuego, by Sylvia Iparraguire.