“It is impossible to say definitely what percentage of the movement of slaves to the lower South was comprised in the domestic slave trade.…”
L. C. GrayGray, History, p. 658.
Between 1790 and 1860 approximately 835,000 slaves moved from the exporting areas to the importing areas of the United States South.Fogel and Engerman, Time on the Cross: The Economics, p. 47. Gutman and Sutch (“Slave Family,” p. 99) estimate “more than a million slaves entered the interstate migration between 1790 and 1860.” For other estimates of the net migration of slaves (or blacks) within the United States, see Collins, Domestic Slave Trade, pp. 61–67; Bancroft, Slave-Trading, pp. 382–406 and sources therein; Lang, Effects, pp. 57–72; Sutch, “Breeding,” pp. 178–80; McClelland and Zeckhauser, Demographic Dimensions, pp. 159–64; and Tadman, Speculators, pp. 237–47. These slaves either moved with their owners as whole plantations or were bought by interregional traders and shipped to the lower South. Until recent years historians had no way of estimating the share of sales in the interregional movement of slaves. Consequently, most of the early quantitative estimates of the interregional slave trade were vague or deliberately imprecise.According to Weld (Slavery, p. 13), “perhaps four-fifths or more” of the slaves were transported through the interregional slave trade. For the period 1820 to 1850, Collins (Domestic Slave Trade, p. 62) estimated that less than two-fifths of the migrants were carried south through the trade. According to Phillips (“Racial Problems, p. 223),” The conjecture of about 25,000 per year which has often been made for the interstate slave trade is probably as just an approximation as can be had.…” Bancroft (Slave-Trading, p. 398) “supposes that” the slave trade accounted for 70 percent of the slave exports. Stampp (peculiar Institution, p. 239) suggests that the slave trade accounted for “perhaps a majority” of the slave exports. According to Miller (“Note,” p. 182), “Estimates indicate that from two-fifths to one-half of these [slaves] may have been sold by their owners and moved by slave-traders to newer regions. Presumption lies in favor of the lower estimate,…”