Directly or indirectly, the economies of all 13 British colonies in North America depended on slavery. By the 1620s, the labor-intensive cultivation of tobacco for European markets was established in Virginia, with white indentured servants performing most of the heavy labor. Before 1660 only a fraction of Virginia planters held slaves. By 1675 slavery was well established, and by 1700 slaves had almost entirely replaced indentured servants. With plentiful land and slave labor available to grow a lucrative crop, southern planters prospered, and family-based tobacco plantations became the economic and social norm.