It is estimated that half to two-thirds of colonial immigrants were indentured servants. As late as 1790, 6% of the population of Kentucky was under indenture. Only about 40% of indentured servants lived to complete their terms.
Indentured servants were more profitable in the short term for land owners than enslaving Indians or free labor. Eventually rising costs of maintaining servants and the desire for land by former servants helped lead to the downfall of the system. Importing African slaves also became more profitable.
In Virginia and Maryland the headright system was introduced. A grant of 50 acres was offered for each person a colonist brought in as a servant. If 25 servants were imported, the "sponsor" was given 1250 acres of land.
Early indentured servants to Virginia came from both Great Britain and Africa.
Next up: The Headright System
[Sources: Wikipedia, USHistory.org, PBS.org]