Featuring the son of a blacksmith from Hartford, FTP, name this novel by Mark Twain.
It begins with the author's encounter with the protagonist in Warwick Castle and ends with a P.S. from the author, who read the Manuscript that details this story.  The protagonist opens his tale by telling how he was knocked out in a duel with a man named Hercules and when he woke up his adventure truly began.  With the help of the erstwhile page Clarence and the lady Sandy, he used his mechanical ingenuity to lead a revolution across England, which he arrived in during the year 528.  Featuring the son of a blacksmith from Hartford, FTP, name this novel by Mark Twain.
It begins with the author's encounter with the protagonist in Warwick Castle and ends with a P.S. from the author, who read the Manuscript that details this story.  
A Connecticut Yankee in King Arthur's Court