Growing up learning that you’re not part of society because you are “other” is something that I think is very dependent on location. Even so, parallels between Gangs of New York and modern depictions of other races can be seen in the US with Native Americans and Alaskan Natives being pushed into specific areas to live; reservations and certain kinds of villages. Ostensibly this is to allow them to continue to practice their culture and beliefs, but the areas they have been pushed into are often less rich in resources than other areas, or are otherwise regulated heavily to the point that they are not able to thrive.
Another place we see this happening is with current refugees fleeing into Europe. While they are legally accepted and generally welcomed, places like Germany do have some blowback, where these asylum-seekers are regarded as less and other. There are those who go out of their way to ensure that these people are made to feel so. While it is not as systemic as the scene from Gangs of New York, it marks the same attitude, that there is still a feeling of specific boundaries set in place that define the natural rights of some people to live in certain places, to the exclusion of all others.
Social structure is another place this can happen, as with the Indian social structure. There is a caste there known as ‘Dalits’ or ‘Untouchables,’ and though there has been a little bit of effort put to moving in the direction of a unified society, there are still many cases of a group of people who are made to be less than the rest of society (and treated pretty horrifically as a result), and therefore other. Some pretty awful injustices come out of this – but then again, whenever there is an instance of a group of people being labeled as inferior to others, that is always the result.