The question was posed in chat by Fred M and it struck my fancy. A short quick search lead me to the following:
What Did People Do Before There Was Kiln-Drying?
A historical discussion about lumber drying in the olden days. June 30, 2007
Question
What did woodworkers do before kiln drying? How did they get wood seasoned for indoor furniture?
Forum Responses
(Sawing and Drying Forum)
From contributor I:
Two things…
One: They were patient, they air dried the wood properly, then brought it inside and completed the drying. This took a couple of years, but it worked fine.
Two: Houses were not centrally heated or air conditioned, therefore wood didn’t need to be as dry as it does in many modern homes.
You can still make fine furniture without a kiln, you just need to dry the wood properly to an inside level. All that’s needed to do this is to sticker your air dried wood in an inside environment, and wait a while. This was taken from the following site
https://woodweb.com/knowledge_base/What_Did_People_Do_Before.html
It is interesting to note that although it wasn’t the norm, kiln drying of lumber reaches way back to the early 1800s, maybe even earlier.
And of course more then you really wanted to know …
https://en.wikisource.org/wiki/Popular_Science_Monthly/Volume_45/July_1894/Kiln-Drying_Hard_Wood