Yes, family and religion. I don't think American society was ever as multi-generational as in Asia or Europe. But, yes, AFAIU back then it was much more common for immediate and even distant families to live under the same roof, long-term or temporarily. Grandpa or Uncle Charlie too old to live alone after being widowed? Move him into your guest room. No hand-wringing negotiation required; no serious disruption to lifestyle.
My grandfather rented his basement to his best friend for years until the friend married, and then the two couples were best friends. It wasn't that the friend had fell on hard times or was wanting for anything; it was just because people back then demanded less personal space and were more comfortable living near or with each other. These days moving into your friends basement is practically a moral failing. I guess maybe because as society has become more diverse we have fewer signals to different in-group people from out-group people; we've been reduced to relying on independence and wealth as the most important markers of people's character.
No, what's changed is expectation. In the 1830's a lot of people just got old and died, were impoverished and angry about it, but what were they going to do? Now we have widespread literacy and a middle class that doesn't expect poverty until you die as a retirement plan.