What man-made profitable industry back-in-the-day was founded on shocking fundamental injustice?

what @Sandy said The slave trade, or otherwise maybe coal mining?,

Now my q, what does this have to do with football?

Cotton cultivation. USA injustice did not end in 1865,

The Church bringing in young lady's from poor Europe. Then putting them to work in Brothels to pay off the debt to be brought to America. Clearance sellers. To immigrate. You had to have so much money on you to enter. There were some who would short loan you that money at high interest to enter & also charge to get you medical clearance if sick on arrival. Loan sharking. Brothels that took children in to work. If there parents became to poor to support them.

This question has nothing to do with Chicago business. Moreover, it is hard to understand what you are asking.

Drinks usually

Chimney sweepers used poor young boys to go down chimneys to clean them out.

British government.

you'd have to go pretty far "back in the day" because slavery has been around for tens of thousands of years.