Tiago Cardoso’s review published on Letterboxd :
Western in outer space (American history).
Gangs of New York should be seen as an "opera, not a documentary". The narrative vehicle of the story is Amsterdam Vallon's revenge on The butcher for his father's dead, this emotional turmoil between the people he runs into it in the "gates of hell", works sustained by the use of the blood as a symbol of the similar vulnerability of all persons (narrow ethnic consciousness) and by the principles of Abraham Lincoln (Declaration of Independence, representing the American unity). That unity is the American citizenship, for which Americans made war, the only basis for a just and lasting peace among all Americans, native and immigrant. (Republicans vs Democrats)
An spectacle of fearsome acts discussing American origin and American Identity.