Why did slave labor in the chesapeake region increasingly supplanted indentured servitude during the last two decades of the 17th century?

improving conditions in England reduced the number of transatlantic migrants.

Indentured servants were men and women who signed an agreement by which they agreed to work for a certain number of years in exchange for transportation to Virginia and, on arrival, food, clothing, and shelter. The number emigrating to New England decreased as living conditions in England improved