"Whereas immigration was somewhat restricted during the 1940s and 1950s, another surge in immigration occured in the 1970s."
I saw this sentence from book, but it's quite confusing. Are "was" and "occured" right expression in this sentence?
I thought 1940s and 1950s means from 1940 to 1959. So I thought "had been" and "had occured" should be used instead of "was" and "occured" because the sentence indicates the period between past to past.
(Not a Teacher)
I will agree with you that this sentence is a bit funky. If I were writing this, I'd say:
"Whereas immigration was (or 'had been') somewhat limited during the 1940s and 1950s, it surged during the 1970s."