Sara Beth W.
Google
I toured all four of the Historic Columbia houses, and I started with the Robert Mills house, though the Hampton Preston across the street is my favorite of all four. Robert Mills is my next favorite - fantastically restored and preserved, and I love how they have it all set up - especially down stairs in the kitchen, with biscuit flour and a cracked egg on the floor (all pretend, of course.) There's a beautiful symmetry and curves to Mill's work (he's the architect, no one family actually lived there in the end, though it was used for other things.) I love the curved front hall and rooms.
I think the tours pre-covid were more guided. The guides told me that they were supposed to stand in the hall while visitors read the plaques, but most of them couldn't help themselves and stood in the door and told me all about everything anyway. Plus, I was the only person on three out of the four tours I took, so I think they were generally more casual.
Also, you get a discount the more tours you take - they came to recognize me over the week I visited, so I paid anywhere from $7-10 for each of my tours.
EDIT - don't sleep on the monthly garden tours, they are really informative and interesting!