From the beginning, some Americans have been able to move more freely than others.

They were called patrollers or, variously, “paterollers,” “paddyrollers,” or “patterolls,” and they were meant to be part of the solution to Colonial America’s biggest problem, labor. Unlike Great Britain, which had a large, basically immobile peasant class that could be forced to work for subsistence wages, there weren’t enough cheap bodies in America to do the grunt work. If you were a planter looking to make your fortune in rice or tobacco—the New World’s cash crops—you had to size up to industrial scale, and for that you needed bodies, armies of bodies, a labor force that could be made to work for terms no less brutal than those inflicted on the miserables of Europe.

Native Americans weren’t the solution, not after disease, war, and murderous forms of forced labor reduced their number by half. Indentured servants were imported, but in numbers too few to fill the void, and they had a habit of running off: the wide frontier beckoned, all that empty space for sass-mouths and malcontents to vanish into. So it became Africans. Jamestown received its first cargo of enslaved humans in 1619, a dozen years after the colony’s founding: “20 and odd Negroes,” according to records, the first installment on the estimated 455,000 who would eventually land in North America.

Control of this new labor force would be key; mutiny was the great fear. By the early 1700s, a comprehensive system of racially directed law enforcement was well on its way to being fully developed.