In the very early days of the city, there was a city rule stating that any prisoner without means of paying his room and board in prison could be "sold" to cover costs after his sentence, and such an auction was held twice. The history books usually call these "slave auctions," but they really shouldn't be confused the sort of slave auctions that were going on in the South at the time. It wasn't quite the same system, in that the prisoners in question would not be slaves for life - just until they had worked off whatever the highest bidder paid. Slavery had been abolished in Illinois in the 1780s.
Several books mention the first auction in the city, in which George White, the town crier better known as "Black George" (or "Darkey George' or any number of names that seem rather rude to modern ears) auctioned off a white vagrant from Maryland named Harper. He was a British man by birth, with wealthy parents, who (from what we know of him) bummed around the city calling everyone "squire." He had been arrested for vagrancy, and, as he had no money and there was no poor house, he was put on sale at public auction.
This makes for an interesting slave auction, since the auctioneer was black and the "slave" was white. White went to his job as auctioneer with gusto, proclaiming that if you had Harper in your house, he could hide whiskey in a place where no one else could be tempted by it. Indeed, it was actually George White who BOUGHT Harper for a quarter. Having won the auction, George marched Harper back to his place, where he was put to work for 30 days or until he had worked off the sale price, at which point he was free to go.
Black George, the town crier and handyman from the 1830s, is an interesting character in Chicago history - he appears briefly in FATAL DROP: TRUE TALES OF THE CHICAGO GALLOWS (see link at right) as the hangman at the city's first hanging. He seems to have been known around town as a serious, peaceful and respectable fellow, though history records him of having played one practical joke: when he saw a barber shop advertising a haircut for 15cents and a shave for 5cents, he went in and asked that his head shaved. He TRIED to pay only a nickel, but, as his hair was not easy to shave, the barber demanded (and eventually got) a quarter.
Not much else seems to be known about George White, but I'm looking into finding out more. He and the other town crier (Black Pete) were well known in the city, not only crying out the news and officiating at executions but putting on nightly shows that were said to beat any minstrel show on the circuit. One myth that has gone around is that historical references usually said he was white, and only dilligent in the late 20th century uncovered the truth. In fact, just about every historical source I've seen, going back to the mid 19th century, mentions that he was black. None say he was white.
As for Harper, most witnesses say he ran like hell and never worked a second for White, who, like the rest of the town, didn't seem to take the "auction" very seriously - it was really just something to humiliate Harper into giving up liquor. It didn't work, though, and Harper was soon a familiar figure wandering drunkenly through the streets and cursing people in Latin (the sherrif later remembered that, when half-drunk, Harper would be "in the viin of the classics." He once sold the rights to dissect his body to a doctor for a dollar in drinking money, but whether the doctor ever collected is unknown.