Little update, got my hands on an 1874 map and the house is present! In fact, I may have even figured out what the "secret room" that has no entrance is under part of my kitchen floor! There is a piece broken out of it on the front, and back which was done to run plumbing through it into the kitchen. It appears to even have a stone/mortar cieling and is as deep as the basement, but not connected.
Right now, due to the fact it has perfectly smooth parged walls which are thick and even a thick stone/mortar cieling and is as deep as the basement, my guess is it was an icehouse. Any ideas? I'm assuming you accessed it through the kitchen floor at the time and this was to keep the "cool" from leaking out.
