Everybody knows about the intimate link between the cotton industry of the American South the the institution of slavery in the United States, I often read or hear that the invention of the cotton gin and its ability to increase profitability "saved" and perpetuated slavery in the South, the expression "king cotton" comes to mind. But I know slaves were also used in other industries, most notably the tobacco industry (at least, I know for sure they were integral to the tobacco industry of the Caribbean pre-British Abolition, and I assume slave labour played as critical a role in the tobacco industry in the United States), and I am asking how big a role chattel slavery played in the United States' economy beyond cotton and textiles.
In "The Half Has Never Been Told," Ed Baptist estimates that in 1836, about "half of the economic activity in the United States derived directly or indirectly from cotton produced by the million-odd slaves-- 6 percent of the total US population-- who in that year toiled in labor camps on slavery's frontier." (Baptist, The Half Has Never Been Told, Basic Books: NYC, NY, 2014. p. 322). Baptist arrived at this estimate by looking first at the revenues that came from cotton and its shipping; then at the second-order effects of activities that made cotton production possible-- the long-distance trade in slaves and land, the supply of credit which made those purchases possible, the cost of food, clothes, and tools for slaves, and the planter class's consumption; then by looking at third-order effects from the sorts of spending that the slavery's supporting industries generated. If Baptist's calculations are right, slavery had a huge effect on the US economy as a whole, in industries like manufacturing, food production, shipping, trade, and finance.