fore which sought luxuries in clothing, precious metal and stones, spices, etc., for the rich, transformed itself to a world-wide trade in necessities incomparably richer and bigger than its medieval predecessor because of its enormous basis of demand. Its first appearance was in the slave trade where the demand for the new American crops showed itself in a demand for the labor necessary to raise them; thus the slave trade itself was at the bottom of the rise of great commerce, and the beginning of modern international commerce. This trade stimulated invention and was stimulated by it. The wellbeing of European workers increased and their minds were stimulated. Economic and political revolution followed, to which America fell heir. New immigrants poured in. New conceptions of religion, government and work arose and at the bottom of it all and one of its efficient causes was the toil of the increasing millions of black slaves.
As the nation developed this slave labor became confined more and more to the raising of cotton, although sugar continued to be the chief crop in the West Indies and Louisiana, and rice on the southeast coast and tobacco in Virginia. This world importance of cotton brought an economic crisis: Rich land in America, adapted to slave methods of culture, was becoming limited,
