Mark Twain Boldly Went to the U.S.S. Enterprise
Star Trek as a franchise celebrates its 51st anniversary today, having debuted on NBC on September 8th, 1966. Over the course of its 726 episodes and 13 feature films, Trek writers relished in their open sandbox they had to play in with with historical figures and literary references, particularly once The Next Generation introduced Holodecks into Trek canon. From Shakespeare to Doyle to Melville, allusions and direct references are abound in the Trek universe. TNG even loved bringing famous people into the fold, notably Data's poker game with Albert Einstein, Sir Isaac Newton and Stephen Hawking.
The two trademarks of Trek collided in the two part episode Time's Arrow, which served as Next Generation's season five finale & season six premiere. Long story short, Data travels through time to late 19th century San Francisco, where he becomes an acquaintance of Hannibal's own Mark Twain. They even make young Jack London a character, before he gained fame in his own right.
They were even able to bring Twain to the Enterprise for a quick tour of the 24th century. Twain was portrayed by a great character actor named Jerry Hardin, who would later have a recurring role on The X-Files.