The Middle Passage: Between 10 and 15 million Africans were forcibly transported across the Atlantic between 1500 and 1900. But this figure grossly understates the actual number of Africans enslaved, killed, or displaced as a result of the slave trade. At least 2 million Africans--10 to 15 percent--died during the infamous "Middle Passage" across the Atlantic. Another 15 to 30 percent died during the march to or confinement along the coast. Altogether, for every 100 slaves who reached the New World, another 40 had died in Africa or during the Middle Passage.

From Servitude to Slavery in the Chesapeake Region, 1619-1690

Because of the massive amounts of tobacco crops planted by families, "indentured servants" were brought in from England to work on the farms.  In exchange for working, they received transatlantic passage and eventual "freedom dues", including a few barrels of corn, a suit of clothes, and possibly a small piece of land

Growth of Plantation Economies and Slave Societies
The Slave Trade - Africans had been brought to Jamestown as early as 1619, but as late as 1670, they numbered only about 2,000 in Virginia-only about 7% of the total population of the South.

In the 1680s, the wages in England rose, therefore decreasing the number of indentured servants coming to America.  By the mid-1680s, black slaves outnumbered white servants among the plantation colonies' new arrivals.

Stono Rebellion, 1739
The Spanish empire enticed slaves of English colonies to escape to Spanish territory. In 1733 Spain issued an edict to free all runaway slaves from British territory who made their way into Spanish possessions. On September 9, 1739, about 20 slaves, mostly from Angola, gathered under the leadership of a slave called Jemmy near the Stono River, 20 miles from Charleston. 44 blacks and 21 whites lost their lives. South Carolina responded by placing import duties on slaves from abroad, strengthening patrol duties and militia training, and recommending more benign treatment of slaves.