Actually, slaves were shipped all over the world.
Why is the United States the only country with a large population of slave decendants?
Edit: for background...
"There is nothing which contributes more to the development of the colonies and the cultivation of their soul than the laborious toil of the Negroes."
King Louis XIV of France, 1670
As the major European powers--Portugal, Britain, France, and the Netherlands--looked for ways to exploit the fertile lands of the New World, they looked to Africa for a steady supply of labor. Soon enslaved Africans had become absolutely vital to the cultivation of sugar, tobacco, cotton, and other goods Europeans craved.Based as it was on unpaid labor, the plantation system produced huge fortunes for many nations, companies, and individuals. And the king of all commodities was sugar. As European demand for sugar began to surge in the 17thcentury, plantations sprang up throughout Brazil and the Caribbean. Sugar cultivation created an insatiable demand for slave labor from Africa. Many plantations produced additional crops such as indigo, rice, and coffee, and the owners used their wealth to diversify into banking, insurance, and other industries.
The United States was officially born in 1776. European courts probably wouldn't settle for this nonsense, so they sue here.
Edit 2: This is a really great, simple read!
http://www.mariner.org/captivepassag...ion/index.html