About a century ago, in central Louisiana, in the town of Harrisonburg, the seat of Catahoula Parish, Arch and Mae Aplin opened a general mercantile store. The Aplins sold everything—dried goods and leather shoes, medicine and cotton shirts, cuts of beef and hammers and nails—and their store was successful, in large part because of its location. Harrisonburg sits on the western bank of the Ouachita River, and back then the town was a hub for travelers. If you were heading east to Mississippi or west into the Louisiana Hill Country, you had to traverse the Ouachita, and the ferry that docked at the bottom of Main Street in Harrisonburg was one of the only ways to do that. The Aplins’ store stood on Main Street, just inland from the ferry. No one crossing the river in either direction could miss it. But the Aplins didn’t just want customers of convenience. They took pride in their store. They called it Arch Aplin’s Biggest Little Store in Catahoula Parish, and they offered travelers products they couldn’t get anywhere else. The Aplins stocked turnip greens they’d harvested on their farm, and they sold syrup they’d made from their own sugarcane. Arch raised cattle…