Johnny Depp adopted Goldeneye, the horse that played Gunpowder, Ichabod Crane's horse in this film, when he heard it was going to be put down.
The idea of The Headless Horsemen actually dates back to the Middle Ages in Europe, largely in Celtic and German folklore. While Washington Irving's horseman can be considered the most famous, most areas of the United States during the time of the story's publishing had their own stories of headless horsemen. Irving's is said to be inspired by the headless body of a Hessian Jägers (renowned sharpshooters and horsemen), who was found in Sleepy Hollow. The real Van Tassels buried him in Old Dutch Burying Ground in an unmarked grave.
Johnny Depp did all of his own stunts for the final scene where he is dragged by the horse. He had bullet-proof clothing underneath his wardrobe.
Johnny Depp initially found the idea of Christina Ricci being his love interest in this film to be rather odd, seeing as he's known her since she was nine years old. They first met on the set of Mermaids (1990), as Depp was dating Winona Ryder at the time.
Historically, Ichabod Crane was a very unattractive man. Johnny Depp offered to add prosthetics to his face to make himself look ugly, but director Tim Burton wanted to base the character on Crane's more unattractive personality traits, his reported squeamishness and eccentricity.
Tim Burton: [cast] Johnny Depp previously appeared in Burton's Edward Scissorhands (1990) and Ed Wood (1994). Likewise, Jeffrey Jones had worked with Burton in Beetlejuice (1988) and Ed Wood. Martin Landau had starred in Ed Wood as well. Michael Gough worked on Batman (1989) and Batman Returns (1992). Almost the entire design team from Batman was recruited for Sleepy Hollow, too.
Tim Burton: [Dracula] The windmill scene from the Hammer film The Brides of Dracula (1960) is imitated. Hammer veterans Christopher Lee and Michael Gough appear.