African labor was used in many ways. In the southern United States, African labor (slaves) was used to harvest crops such as rice and tobacco. The demand for slaves increased when cotton growing became more profitable. This occurred after the cotton gin was invented. With the cotton gin, cotton could be grown easier throughout the entire southern United States. The cotton gin separated the seeds from short staple cotton by machine. Before the cotton gin, the seeds had to be separated by hand. This was a time consuming process. Since short staple cotton could be grown anywhere in the South, the production of cotton increased tremendously. Thus, more slaves were needed. Another way slaves were used was to do household chores for the plantation owner. The slaves that worked in the house were called house slaves. Slaves were used in many ways throughout the South. In the North, slaves were used in artisan trades and were even educated. Phyllis Wheatley was a Northern slave who was educated to be a poet.