Just because it was the law doesn’t mean it was enforced as written. But one way people got around it was the landlord rented the apartment to one or two or three people and any others weren’t on the lease. The locks on bedroom doors doesn’t typically happen when you and I rent an apartment together and find two other people to share the rent. It happens when a landlord rents individual bedrooms to strangers who don’t know each other.
I guess that works pragmatically, but it’s hardly a good result legally. When I was a student, over 20 years ago now (where does the time go?!), we rented a house jointly as a group of friends, and we were specifically told locks on the doors were forbidden. Seems like NYC could have had a similar law rather than a cap on number of unrelated tenants.
Something else I was thinking about: wasn’t there a thing known as a ‘Boston marriage’ where two women lived together, ostensibly and in many cases actually as friends? So these laws against unrelated women living together cannot have been that prevalent.
In the UK, after the first world war, so many men had been killed that a significant number of young women were unable to marry, and were therefore obliged to work, support themselves, and live alone or with another woman. It wasn’t seen as a desirable state, but it did become socially acceptable, and AFAIK that has never changed since.
Now that’s no way to practically increase the birthrate.
Preferable to a sock on the door handle, no? 
There were exceptions for dorms. And yes, it did discourage young women who just got their first job. They were expected to live with their parents or their husband.
Do American students typically live in dorms all 4 years?
Was that still true when you were that age?
I can’t find any statistics about what percentage live on campus all four years. All I can find in a search is that some live in a dorm all four years, some three of four years, some two of four years, some one of four years, and some none of four years. Of course, it’s also true that 32.9% of Americans who start college drop out before finishing.
IMO It depends heavily on what the local housing options are.
Some colleges provide nothing but dorms. Others have extensive holdings of conventional apartment buildings. Some colleges almost everyone lives in college-owned housing of one form or another, while other colleges are attended mostly by people who live some distance away and commute to school each day. Some colleges are surrounded by “student ghettos” of privately-owned cheap rental housing, both apartments and free-standing houses. Other colleges have almost nothing of the sort nearby.
I’m guessing most of those who move to NYC to attend college do unless they are either from a wealthy family or don’t mind a long commute. I know some places have relatively inexpensive housing near colleges - but not in NYC, at least not near the colleges anyone would move here to attend.
Or if it was absolutely necessary, they could live in a place like the Barbizon Hotel for Women where men could not visit the residential floors and the women had a curfew. Which is not all that different from living with your parents.
Remember that until after WWII it was almost unheard of for women to go to college, so… it didn’t come up. Where/when women were admitted to higher education they were housed in dorms or homes where they were very strictly supervised..
Pre-married women who worked almost always still lived at home - that was what the women in my parents’ and grandparents’ generations did.
Never heard of related women being barred from renting together, but women being required to get a male co-signer for a lease (father, brother, etc.) could be required.
It was not. Heck, we had coed dorms when i was that age. When my mother was in college, the women’s dorms had all sorts of rules about visitors, and when men could visit, and how far the door had to be open. There’s a reason that generation went to "lovers Lane"s and often had sex in cars. I’m pretty sure most of my generation preferred bedrooms.
This isn’t really true, The percentage of people who went to college (in the U.S.) was smaller. This was true for both men and women. In 1940, 5.5% of men graduated from college, while 3.8% of women did. The percentage of both men and women then increased, but the percentage of women increased more. In 2014, the percentage of women who graduated was larger for the first time.
It appears that many cities and states in the U.S. had rules that no more than X women could live in the same apartment/house, where X could be various numbers. It appears that since about the 1970s these laws have been disappearing. It appears that even when such laws still exist, they are mostly ignored.
Depends…are the doors locked from the inside or the outside?
This was about NYC in the 90s, though. And applied to both sexes.
Big change in one generation.
I’m sure I heard more women than men have been going to college in America since the 70s?
That’s a question isn’t it?
And who are you keeping in/out?
Probably not quite that long, but multiple decades for sure.
But there are vast differences in the USA between “started attending college”, “is attending college”, and “has graduated from college”.
The answer numbers for those three categories could be decades apart.
Our beastly system produces far more college dropouts than it does college graduates. Sometimes for academic reasons, but more often for lifestyle / affordability reasons. Which reasons are very unequally distributed by gender.
Outside - so no one can go into the room and steal a person’s stuff when they’re not home. Maybe inside too - I wouldn’t have seen that. Remember, I said it normally happens when the landlord rents individual bedrooms to people who don’t know each other.
Whoosh.