Like today’s titans of industry, planters understood that their profits climbed when they extracted maximum effort out of each worker. So they paid close attention to inputs and outputs by developing precise systems of record-keeping. Meticulous bookkeepers and overseers were just as important to the productivity of a slave-labor camp as field hands. Plantation entrepreneurs developed spreadsheets, like Thomas Affleck’s “Plantation Record and Account Book,” which ran into eight editions circulated until the Civil War. Affleck’s book was a one-stop-shop accounting manual, complete with rows and columns that tracked per-worker productivity. This book “was really at the cutting edge of the informational technologies available to businesses during this period,” Rosenthal told me. “I have never found anything remotely as complex as Affleck’s book for free labor.” Enslavers used the book to determine end-of-the-year balances, tallying expenses and revenues and noting the causes of their biggest gains and losses. They quantified capital costs on their land, tools and enslaved workforces, applying Affleck’s recommended interest rate. Perhaps most remarkable, they also developed ways to calculate depreciation, a breakthrough in modern management procedures, by assessing the market value of enslaved workers over their life spans. Values generally peaked between the prime ages of 20 and 40 but were individually adjusted up or down based on sex, strength and temperament: people reduced to data points.
