Daniel Day Lewis and Bill Poole could be twins. They are both known for their curly mustache, dark hair and skinny chin. Leonardo DiCaprio and his role as Amsterdam Vallon, both had very similar features. Brendan Gleeson played Walter 'Monk' McGinn. They both are short and had/have a very round soft face. "Hellcat Maggie," AKA Jenny Everdeane , had filled fang teeth in 1850. The costume designers did a great job transforming Cameron Diaz to look the part.
All of these where real people who lived in 5 points in the 1850's.