Question: How many acres is the district in Selma where  the most popular style of house in the Southern United States from the end of the American Civil War (1861–65) through the 1920s be found?
Sentence (from "Shotgun house"): A railroad apartment is somewhat similar, but instead of each room opening onto the next room, it has a side hallway from which rooms are entered (similar to compartments in passenger rail cars).
Relevant evidence: No