The audio is probably the best way if you have the time, but there is a short text summary as well as a transcript.
In the early 1800s, [slave patrollers] were the de-facto police force in the South, and it was their job to catch runaway slaves and [to] make sure that any black person walking down the street had their papers. They could stop [and] detain any black person, demand to see their papers, and, of course, if you didn't have license to move around freely, you were beaten, taken back to your master, jailed, and it was an early version of stop and frisk. Any white person with the slightest authority could demand to see the bonefides of any black person walking around.
Of course, growing up in the city, I'm acquainted with stop and frisk, with being pulled over by cops, being handcuffed and questioned as I'm going out about my business. ... We have a new name for it — "stop and frisk" — and 200 years ago it was "law and order."
a tip of the hat to Sukie