The Domestic Trade Forces a Million More South After Importation Ends
Historians call it the Second Middle Passage: cotton's expansion drives an internal slave trade larger than the international one it replaced
Quick facts
- Period
- 1810s-1860s
- Estimated relocated
- approximately 1 million (Walter Johnson estimate)
- Share via organized trade
- about two-thirds
- Destination region
- Deep South cotton states
What happened
After the United States banned the importation of enslaved people from abroad in 1808, the domestic slave trade within the country's borders grew to fill the labor demand the international ban could no longer meet, particularly as the cotton gin made cotton newly profitable across the Deep South. Enslavers in the Upper South, in states like Virginia, Maryland, and North Carolina, where declining soil fertility had made tobacco less profitable, increasingly sold enslaved people to planters establishing new cotton plantations in Mississippi, Alabama, and Louisiana. Historian Walter Johnson's estimate, cited by America's Black Holocaust Museum, puts the number of enslaved people forcibly relocated from the Upper South to the Lower South at approximately one million, roughly two-thirds of them moved through the organized domestic slave trade rather than by enslavers relocating with the people they already held. This forced migration, which historians call the Second Middle Passage, was more than twice the scale of the transatlantic Middle Passage in terms of people directly affected.
Why it matters
The domestic trade demonstrates that banning the international slave trade did not shrink American slavery, it relocated its human cost internally, breaking apart families across enormous distances within the country's own borders on a scale larger than the transatlantic crossing itself. It is the direct mechanism by which slavery expanded into the Deep South's cotton economy even after the legal door to Africa had closed.
How we know
America's Black Holocaust Museum's summary draws on historian Walter Johnson's Soul by Soul: Life Inside the Antebellum Slave Market, and the National Archives holds customs manifests documenting individual coastwise shipments of enslaved people between US ports after 1808, used to verify compliance with the international ban.
Sources
- America's Black Holocaust Museum. What Was the 2nd Middle Passage? · General sourceabhmuseum.org · Cited as a "reference" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- National Archives. The Slave Trade · Primary source (author-declared)archives.gov · Cited as a "primary" source (no stronger domain match).
See something wrong? . Corrections with a source get fixed fastest.
Part of a timelineThe Atlantic Slave Trade29 events · Four centuries in which European traders forced an estimated 12.5 million Africans onto ships bound for the Americas, and the enslaved people, revolts, and abolitionists who fought it from the first crossing to the lastView all →