By the 1730s, slave-built levees stretched along both banks of the Mississippi for a distance of nearly fifty miles. These early levees, made of earth reinforced with timber, failed frequently. But they established a pattern that endures to this day. Since the city wasn’t going to move to suit the river, the river would have to be made to stay put. With each flood, the levees were improved—built higher and wider and longer. By the War of 1812, they extended for more than a hundred and fifty miles.
