Undoubtedly true.
Jewish people were excluded from “polite” company and created their own country clubs with the Catholics.
The Catskills resorts were created for much the same reason — summer camps for Jewish kids because their kids couldn’t get into the “good” ones.
Boston University is another example. I think it is technically Episcopal, but it’s always been a majority (or near majority) Jewish because Harvard had reverse-affirmative-action against Jewish students.
Lots of letters inviting me to join some Jewish student organization while going.
Surprised the Baptist MLK, Jr. went there for his PhD.
The Catholic immigrants funded the founding of Boston College. JF'nK managed to sleaze his way into its law school very late in the semester after losing his first run for Congress.