A Connecticut Yankee in King Arthur's Court

A Connecticut Yankee in King Arthur's Court is a time travel story by Mark Twain that was first published in 1889. As the title suggests, it depicts a time traveller venturing to the court of King Arthur. The Connecticut Yankee quickly endears himself to King Arthur, outduels Merlin (by using his knowledge of 19th Century science), and ultimately modernizes England by means of slow change until medieval Camelot resembles a city in 19th Century New England. He and the changes he brought to England are ultimately beaten back by the forces of the Catholic Church (Twain's trademark anti-religion stance is more noticeable in this book than in his other famous novels). The book has been adapted for film at least twice.