It seems like there's something deficient in the way we tell the story of the history of software architecture (to the extent we tell a story at all) in terms of the name-brand techniques and technologies involved, rather than in the actual layout and organization of actual codebases.
For a while I've assumed that OOP as in C++/Java essentially formalized modular programming in C. In other words, that people were already writing programs whose state was divided into functional areas, with some functions serving as the interfaces between the modules. With a class-based system you can rigidly formalize this; and then OOP as we use the term essentially just reinterprets this formalization as actually creating the architectural paradigm that had already evolved as programs grew.
(This is NOT meant as the one way to sum up the whole world of things identified as or related to "object-oriented programming".)
For a while I've assumed that OOP as in C++/Java essentially formalized modular programming in C. In other words, that people were already writing programs whose state was divided into functional areas, with some functions serving as the interfaces between the modules. With a class-based system you can rigidly formalize this; and then OOP as we use the term essentially just reinterprets this formalization as actually creating the architectural paradigm that had already evolved as programs grew.
(This is NOT meant as the one way to sum up the whole world of things identified as or related to "object-oriented programming".)
But I wasn't around at the time...