Book excerpt: An award-winning historian reveals the harrowing forgotten story of America's internal slave trade—and its role in the making of America. Slave traders are peripheral figures in most histories of American slavery. But these men—who trafficked and sold over half a million enslaved people from the Upper South to the Deep South—were essential to slavery's expansion and fueled the growth and prosperity of the United States. In The Ledger and the Chain, acclaimed historian Joshua D. Rothman recounts the shocking story of the domestic slave trade by tracing the lives and careers of Isaac Franklin, John Armfield, and Rice Ballard, who built the largest and most powerful slave-trading operation in American history. Far from social outcasts, they were rich and widely respected businessmen, and their company sat at the center of capital flows connecting southern fields to northeastern banks. Bringing together entrepreneurial ambition and remorseless violence toward enslaved people, domestic slave traders produced an atrocity that forever transformed the nation.