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.
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.
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...