For what purpose were slaves used for?

In the United States slaves were used to do the daily duties that were considered labor intensive, or labor that could be passed on to others. For example, female slaves commonly worked in the house, cooking, cleaning, things a maid today would do. Male slaves did more labor intensive jobs, working the the fields, building, etc. Of course there aren't the only jobs, but a small list to give you an idea of their purpose.