Jack London was an American author in the late 19th century and early 20th century. London held a number of professions in his lifetime, including working as a "newsie", an oyster pirate, and cutting fish at a cannery.
In 1893, London was working as a bellboy at the Hotel Brian in San Francisco. It was in this capacity that he met Lieutenant Commander Data, a temporally-displaced android Starfleet officer from the year 2368. Believing Data to simply be an eccentric Frenchman, London helped him to acquire goods and supplies which Data needed to track the time shifts of a group of Devidians who were harvesting Human neural energy for sustenance. (TNG: "Time's Arrow")
London even encountered writer Samuel Clemens, who was attempting to gain more information on Data, whom he believed to be the beginning of an invasion from the future. London attempted to convince Clemens to write London's life story, but Clemens advised him that the only person qualified to do so would be London himself, and encouraged him to follow his dream of traveling to Alaska. (TNG: "Time's Arrow, Part II")