In 1965, as the United States raced toward the moon, Martin Luther King Jr. met plantation workers in the Deep South who had never seen or held a piece of official American currency. They were paid in scrip, private money issued by an employer and good only at the employer’s own store. This episode explains how a practical fix for remote logging and mining camps, where shipping cash was dangerous, hardened into a system for keeping workers in place through inflated prices and steep exchange fees.

The record is not all grim. In Wisconsin lumber camps, homesteaders redeemed scrip for the boards they needed to build farms, and in crises from Germany after the First World War to military bases in Iraq and Afghanistan, improvised money kept trade alive. But in Appalachian coal towns and on Southern plantations, scrip engineered debt and dependence. Though Congress outlawed coal scrip in 1967, the urge to pay people in money that only works inside the company has resurfaced in digital form.

• About 75 percent of all scrip issued in the United States came from coal companies, which advanced wages early at only 50 to 80 percent of their value.
• Hawaiian sugar plantations issued a 12 and a half cent coin that stood for an entire day of labor in the cane fields.
• In the Thibodaux massacre of 1887, Louisiana sugar workers striking to be paid in real currency were crushed by militias, and dozens were killed.
• A Devon copper mine, Wheal Friendship, paid workers in poker chips that local merchants accepted, and the village took the name Chipshop.
• In 2008 the Mexican Supreme Court barred Walmart de Mexico from paying staff partly in store vouchers, and in 2019 Amazon warehouse workers were reported to earn Swag Bucks redeemable only for branded merchandise.