The urban Baltimore neighborhood of Hampden-Woodberry began as a mill village in rural Baltimore County, where the swift-flowing waters of Jones Falls provided the power for early gristmills. As the nearby city grew into a major international port, the flour mills gave way to cloth mills that turned out cotton duck for sails. At their peak, the mills of Hampden-Woodberry turned out 80 percent of the worlds cotton duck. Thousands of men, women, and children were employed in what was, in the late 19th century, the United States largest concentration of factory labor. Fortunes were made by such...