Franklin and Armfield was the largest and most powerful domestic slave trading company in the United States between 1828 and 1836, and it was likely the largest and most powerful in American history. Founded by Isaac Franklin and John Armfield, the company purchased thousands of enslaved people in Maryland and Virginia, forced them to walk hundreds of miles overland or trafficked them by ship down the Atlantic coast into the Gulf of Mexico, and sold them in Louisiana and Mississippi. Capitalizing on a declining tobacco economy in the Upper South, booming sugar and cotton economies in the Lower South, and expanding national banking and credit systems, Franklin and Armfield not only ravaged the lives and families of the enslaved men, women, and children it bought and sold. It also transformed the domestic slave trade from a haphazard, short-term pursuit into an organized profession, demonstrating the trade’s capacity as a big business whose violence and exploitation could generate enormous profits and social respectability for its operators. For decades after Franklin and Armfield shut down, its business model served as the template for dozens of interstate domestic slave trading companies and set the standard for an especially malevolent form of American entrepreneurship.