Something that surprises often is that NYC used to be far, far denser. See the second image: https://urbanomnibus.net/2014/10/the-rise-and-fall-of-manhat...
I recommend to people the Tenement Museum for their second trip to NYC - it was eye opening (but pretty grim)
What amazes me is that people did not flee. I assume the hand-to-mouth existence they had in these slums was apparently a little better than their prospects elsewhere. Or perhaps they were moving out but immigration and reproduction was more than making up for it…
To where?
You have no money, very little skills, you don't speak English. Even if you cobbled together money to take the train to some small town in Ohio or Iowa or something, what are you going to do as a complete social outsider who doesn't speak the language?
The idea was to stick around in the LES where you had an actual community. Try to make some money, learn English, develop some skills, and then move out. Which is exactly what people did. And the new immigrants took their places.
Also -- they had already fled. This was the fleeing. From Ireland, from Italy, from Poland, etc.
Sure, my point is that - no matter how bad this looks, it was approximately better than their alternatives. So it's a testament to human resilience.
That aside, that there was literally no going back, given the travel to get to NY. I had an ancestor come to NYC in the 19th c. and return back to Sweden, but he was not in the desperate straits that many were. I'm sure some would have returned, given the opportunity.
There is a real human tendency to stay in a known but bad situation instead of making the risky leap into the likely better but unknown.
You see it time and time again.
Their kids were the ones who were better educated and could move on.
It’s still happening today.
This is the entire reason why people emigrate.
A lot of these people were in immigrant enclaves. Their neighborhoods may have been the only place in the country people spoke their language or shared their religion, so serving that community was their best bet for employment.