Mali was unlike Ghana in that O Mali had a gold-salt trade
O Ghana rejected Islam
O Mali was a center of Islamic learning
Ghana had almost no trade

Ifound this on google “simply, the working conditions were terrible during the industrial revolution. as factories were being built, businesses were in need of workers. with a long line of people willing to work, employers could set wages as low as they wanted because people were willing to do work as long as they got paid.” i hope this you for what your looking for.

Slave labor.  slave labor was an essential part of the economy of spanish polish colonies.