The term I am familiar with prior to that was "immediate family" (as opposed to "extended family").

You come across the term a lot in old genealogy books. For instance in "The History and Genealogy of the Prentice, Or Prentiss Family" (from 1883) contains:

> All his immediate family, himself, wives, and children, are dead.

https://www.google.com/books/edition/The_History_and_Genealo...

Nuclear family is indeed a recent development and started with industrialization and modern capitalism. While we use the same term, 'family', to refer to (pre-)historic forms of family, too, those family types had little or nothing in common with the modern definition, when it comes to power, inheritance, law, sex, love.

https://en.wikipedia.org/wiki/The_Origin_of_the_Family%2C_Pr...