When I was very little, we lived in a house like that, except not in bad condition. Long story, but we were quite wealthy, and then very suddenly, never again. Lol.

Anyway, my brother and I decided it would be fun to sled down the stairs one day, and toward the bottom of the stairs one of us hit one of those little metal strips that held the carpet down on the stairs with the edge of the sled. When my dad was fixing it later they discovered that the stairs lifted up Munsters style, and there was an entire room down there, under the floor, with a tunnel that lead God knows where.

Turns out it wasn't satanists, but was in fact part of the underground rail road, and was used by folks smuggling slaves up north. Ridiculously cool to thing to have in your house

Make sure to movie your teenage kid into that new room!

I mean, yeah. It's just a different style altogether. Parlors and room number has nothing to do with what the house looks like and the architectural era it belongs to.

It would be more accurate to say that it smacks of the gilded age (a time of the greatest wealth disparity in our history) than of the civil war era, even though that still isn't quite right, as the Victorian era is its own thing outside of the Edwardian era.

The US has had more than one age of servitude beyond just the obvious slavery era, sorry to say. It's kind of our brand.

I would click through some of the examples in your wiki link and try and notice a few things that most of the antebellum houses have in common. They're usually defined by the their blocky shape and the large columns in front; very Greek-revival.

This house, however, has completely different details and layout. Beyond the fact that it's missing the telltale columns and imposing silhouette, the design is more intricate and a touch more delicate. The Victorians loved fine details, and were very 'extra' in that way.

But honestly, all of that aside, the biggest tell is just the date it was built. A different style was simply the fashion then compared to earlier in the century. Just like how mid century modern was it's own thing outside of WW2 era suburban homes, though they're similar.

https://en.wikipedia.org/wiki/Antebellum_architecture

It's a specific style dating back to the era of slavery. A lot of old plantation-type houses in the South have the style, and it's... grotesquely romanticized in some corners as a more 'rustic' time.

Big parlour.

Large number of rooms.

Display of wealth and status in a rural area.

I feel like if you were going to own human beings then you would want to do it while living in an Antebellum Style home.

The Emancipation Proclamation was declared in 1862, well before this house war erected.