Not long ago, I decided spur of the moment to attend an estate sale in my Washington, DC, neighborhood. As I walked the few blocks to the address I’d seen advertised, I admired the beauty of the late-nineteenth-century row houses that line the streets where I live. I love their bay windows, turrets, and decorative brickwork. I didn’t really need to buy anything; mostly, I wanted the chance to see inside one of these historic homes. As I ambled down the sidewalk, I hoped that the house hadn’t been renovated too much—as a historian, I always regret it when the original moldings and fireplaces and other pieces of charming old architecture have been stripped away. Article continues after advertisement As soon as I climbed the front steps and went in through the door, I understood this estate sale had not been quickly thrown together by a bereaved family member—clearly, professionals had been called in, and for good reason.…