HARPERSVILLE, Ala. — Word travels fast in this small town, so when Theoangelo Perkins heard that the family of Bill Parker was visiting his grave, he jumped in his car and raced to the old cemetery.

A fire that ravaged Nottoway Plantation, one of the Deep South's largest pre-Civil War mansions, sparked a wave of mixed reactions online, ranging from jubilation to dismay. The Louisiana landmark, ...