In the 17th century, Europeans began to establish settlements in the Americas. The division of the land into smaller units under private ownership became known as the plantation system. Starting in Virginia the system spread to the New England colonies. Crops grown on these plantations such as tobacco, rice, sugar cane, and cotton were labor intensive. Slaves were in the fields from sunrise to sunset and at harvest time they did an eighteen hour day. Women worked the same hours as the men and pregnant women were expected to continue until their child was born.
European immigrants had gone to America to own their own land and were reluctant to work for others. Convicts were sent over from Britain but there had not been enough to satisfy the tremendous demand for labor. Planters, therefore, began to purchase slaves. At first, these came from the West Indies but by the late 18th century they came directly from Africa and busy slave-markets were established in Philadelphia, Richmond, Charleston, and New Orleans.
The death-rate amongst slaves was high. To replace their losses, plantation owners encouraged the slaves to have children. Child-bearing started around the age of thirteen, and by twenty the women slaves would be expected to have four or five children. To encourage child-bearing some population owners promised women slaves their freedom after they had produced fifteen children.