Trivia: As usual, Jackie Chan made his stunts all by himself, but with a new trick on the list: he had never ridden a horse before.
Trivia: At one point, Roy casually mentions his real name is "Wyatt Earp." Wyatt Earp was a famous frontiersman who among other things was a gambler, gunslinger and lawman. He was also involved in the gunfight at the O.K. Corral.
Trivia: The character Nathan Van Cleef is named after actor Lee Van Cleef, who famously appeared in many western films, including classics like "The Good, the Bad and the Ugly."
Answer: During the Qing Dynasty it was compulsory for men to wear a queue to prove loyalty to the Manchu rule. Refusal to follow can result to execution considering that as treason. Also, he not only prevented him from going back to China but also preventing him from informing the Emperor of his crimes without his queue.
Yes, but in fact, Jackie Chan wasn't wearing a queue in the movie. He only had the pony tail. His head should have been shaved half bald, especially if he was the Emperor's Guard. They just didn't want to show Jackie Chan in a half-bald hairstyle.
Similarly happened in 1976 film Hand of Death in which Jackie co-starred in. That film too was set in the Qing Dynasty but all men still had their queues but no shaved temples. The slaves in Shanghai Noon however some of them did actually have that hairstyle correctly having both queue and front temples shaved bald.