1. The rise of the plantation economy: The mid-1700s saw the rise of the plantation economy in Virginia. This was due to the increased demand for tobacco, which was a major cash crop in the colony. Plantations required a large labor force, and enslaved Africans were the main source of labor.
2. The Atlantic slave trade: The Atlantic slave trade was a major source of enslaved Africans for the Americas. The trade brought millions of Africans to the Americas, and Virginia was one of the major recipients of these slaves.
3. The legal status of slavery in Virginia: Slavery was legal in Virginia from the early days of the colony. The colony's laws made it difficult for enslaved Africans to gain freedom, and they were subject to harsh punishments.
4. The demographics of Virginia: Virginia's population was growing rapidly in the mid-1700s. The influx of European settlers increased the demand for labor, and enslaved Africans were seen as a cheap and easily exploitable source of labor.
As a result of these factors, the mid-1700s saw a significant increase in the number of enslaved Africans in Virginia. By 1750, enslaved Africans made up over 40% of the colony's population.