Other: In the scene of Bill the Butcher laying in bed with the naked women, one woman has a noticeable tan line from a bikini - a bit early for the bikini...

Factual error: In a scene set in 1862 or 1863 Bill the Butcher says: 'An Irishman will do for a nickel what a ****** will do for a dime or a white man for a quarter'. The first nickel 5 cent piece was coined in 1866. At the time of the scene the 5 cent coin was a small silver coin called a half-dime.

Continuity: At several times during the movie, Butcher Bill's glass eye changes to what looks like a normal eye. Also, if it is a glass eye, it shouldn't move along with his real eye. It should stay in one spot because no muscles are attached to it.

Continuity: After Bill the Butcher stabs and beats Amsterdam's face badly (and brands him with a hot knife) notice how as time passes the wounds heal then reappear in varying degrees of severity. This is particularly true with the branding, which is almost absent by the end.

Factual error: In the scene where Amsterdam kills the man that shot Bill the Butcher on the shoulder at the theater, you can see bananas on the floor. Bananas were traded in the U.S. only after the Civil War.

Factual error: When the Lords and posh folk are playing snooker they are using plastic tipped cues with blue chalk on the tip. These would not have been used in this time period.

Continuity: After Jenny gets mugged at the dock, the shot shows her pulling herself to a standing position on a crate. In the next shot, from farther back and up high, she is crawling over to the crate she just pulled herself up on.

Continuity: When Amsterdam arrives in New York City and is talking to his new friend, the bag he is holding switches from being held under his arm (camera shot from front) to being carried on his back (camera shot from the back). This happens at least four times in a row during the same scene.

Other: Towards the end of the movie, when the mobs are breaking into stores/houses, the police come to try and stop them. The mob starts to throw rocks at the police. You can see one of these rocks, which look like they should be heavy, bounce right off of one of the officers' heads, and just bounce around as it hits the ground, like it weighs nothing at all.

Factual error: In one scene where Bill is in the Mayor's office, the mayor is sitting behind his desk and holding a bunch of papers, and on the upper right hand corner of the papers is a paper clip. Paperclips were not invented until 1899.