(Note: I've seen the question [What's the difference between 'fowl' and 'poultry'?](https://english.stackexchange.com/questions/61140/whats-the-difference-between-fowl-and-poultry) but I am not asking about the definition, rather the historical usage pattern.)

In modern English we talk about chickens (the bird) and chicken (the meat), as in a plate of chicken, or some chickens in a farmyard.

I read a lot of older novels, particularly from the early 19th c. (Dickens and so on) and have often noticed that they don't talk about chicken, or chickens. The word "fowl" is used. For example, in Dickens' *Little Dorrit* there is a mention of "cold fowl or hot boiled ham"; in Wilkie Collins' *The Legacy of Cain* "he had a fowl for his dinner"; in Gaskell's *Cousin Phillis* there are "speckled fowls" pecking in the yard.

Nobody would call a chicken a fowl today, even less so when talking about the meat. And yet we still talk about pork, beef, etc. the same as ever. When did this terminology change, and why?