I came across this stunning statement in Roxanne Dunbar-Ortiz's [[Not A Nation of Immigrants]]: > [the US had ] a thriving, legal domestic slave market, which by 1840 was of greater monetary value than all other property combined, including all the gold in circulation, all bank reserves, and all real estate. She attributes this to: Walter Johnson, River of Dark Dreams: Slavery and Empire in the Cotton Kingdom. Belknap Press of Harvard University Press, 2013. I asked ChatGPT-5 to help me verify this claim. What it concluded was close. Based on various sources, slavery had become the single biggest asset class by 1840, and it exceeded all other asset classes combined (banks, factories, land, railroads, etc) by 1860. --- **ChatGPT-5's Primary Sources** - **U.S. Census of Wealth (esp. 1850, 1860)** – These provide valuations of land, slaves, livestock, and manufacturing capital. - **Gavin Wright, Slavery and American Economic Development (2006)** – Offers detailed discussions of regional and national wealth tied to slavery. - **Claudia Goldin & Frank Lewis, “The Role of Slavery in the Economic Development of the United States” (1975)** – Early quantitative analysis of slave wealth vs. other forms of wealth. - **Robert Fogel & Stanley Engerman, Time on the Cross (1974)** – Controversial in interpretation, but contains widely cited data tables on slave prices and aggregate values. - **Thomas Piketty, Capital in the Twenty-First Century (2014)** – Uses long-run wealth data to compare slave property to national wealth, drawing on census and secondary research. - **Edward Baptist, The Half Has Never Been Told (2014)** – Narrative-driven but includes aggregated estimates of slave wealth and its centrality to the U.S. economy.