(I think my original post got lost in the thread)
philosopher/clearheaded:
I’m not going to put this the right way, but….
It was a very different time then (Kosher King!), not only in the practice of Tznius, but in the lessened hypersensitivity of men towards women.
It was possible for guys to talk to girls L’Toeles and not sin without strict rules of the shidduch date. That is not possible with the separated-gender society we have today. The Agudah was known to have a mixed picnic for men to meet ladies in the 50’s, because it was L’Toeles.
Not to say that one should stam “shmooze” with a girl (for a boy). But “L’Toeles” was much less formalized. And one should know themselves.
Now as well, once a boy and girl who are unmarried get older and have been in the workforce for some time, the opposite gender loses the “hypersensitivity” of needing to sin when a boy sees a girl. At that point one can loosen the “rules” of shidduch dating (take that as you will).
Wolf got my second point with the Gezel.
And I highly recommend mixed swimming (with wife). It was a regular night activity during the early part of our (Ittisa & I) marriage.