Slavery developed in the American context beginning in the seventeenth century, and the institution was continued with various justifications for more than two and one-half centuries. The slave trade in Western Europe developed in the fifteenth and sixteenth centuries. Slavery had a long history by that time, and slavery in Africa was a well-established institution. African slavery had one difference for most of its history:
At least in some portions of Africa there was no racial basis of slavery. The Egyptians enslaved whatever peoples they captured. At times they were Semitic, at times Mediterranean, and at other times blacks from Nubia.
Historians have offered differing perspectives on the reason why slavery developed in the Americas and what differences may be found between slavery in Africa and slavery in America.
In the American context, most slavery did have a racial component though one that developed over time. Basil Davidson traces the development of attitudes on the part of European settlers not only toward black slaves but toward the Indians encountered on the frontier. The slave trade developed at the same time as Europe began exploring new realms and encountering new peoples, and it was necessary for the white European to develop some philosophical attitude which placed himself and the "noble savage" he encountered in the wild on some sort of scale. The idea of the noble savage would give way to the view that the savage was simply inferior, but in the beginning explorers like Charles Wheeler saw the savage as closer to nature and thus more noble and happier in contrast to the European:
A Guinean. . . by treading in the paths prescrib'd by his ancestors, paths natural, pleasant, and diverting, is in the plain road to be a good and happy man; but the European has sought so many inventions, and has endeavour'd to put so many restrictions upon nature, that it would be next to a miracle if he were either ...