The Atlantic slave trade or trans-atlantic slave trade took place across the Atlantic ocean from the 16th through to the 19th centuries. Most of the of slaves transported to the New World were Africans from the central and western parts of the continent.  The numbers were so great that Africans who came by way of the slave trade became the most numerous old-world immigrants in both North and South America. The first Africans imported to the English colonies were also called “indentured servants”.  They were merchandise or units of labor, and were sold at markets with other goods and services.