Jack London (January 12, 1876 – November 22, 1916) was a human from Earth who lived during the 19th and 20th centuries. An author, he is perhaps best remembered for writing The Call of the Wild and over fifty other works.
In 1893, London was working at a hotel in San Francisco, California. It was during this time that London encountered Lieutenant Commander Data, who had traveled back in time from the mid-24th century. London also met Samuel Clemens a short time later, and let him into Data's room at the hotel so Clemens could see the strange materials Data had assembled. This led Clemens to believe that there was a conspiracy which could be a prelude to invasion. London also asked Clemens for advise on how to be a good writer, and asked him to remember the name Jack London. (TNG episodes: "Time's Arrow, Part I", "Time's Arrow, Part II")