Explore how slavery was brought to the Americas and its important in the early economy of the colonies?

Slavery in a sense was here in the Americas before white people discovered the new world.  Native peoples took prisoners from other tribal or cultural groups, who were treated in various ways.  The Aztecs took prisoners in war for human sacrifice, the Caribs took prisoners to be slaves and for cannibalism, and pretty much all North American natives took prisoners in war and put them to work as, essentially, slaves.  Some would earn the status of free members of the tribe, but some did not.

Slavery as a "civilized" institution began almost as soon as the Spanish arrived.  The Spanish not only enslaved the Native Americans but began importing slaves from Africa as early as 1502.  Slavery in the British colonies did not begin until 1619, when Dutch merchants traded Africans as slaves to Virginia colonists for agricultural products.  The early slaves in Virginia were, however, treated as indentured servants and set free with pay after seven years.  Chattel slavery, the concept of slaves as property in the same sense as livestock, began in the British colonies in 1644 in Massachusetts.

Racism came even before slavery.  The Spanish felt superior immediately to the "savages" they discovered in the New World, and treated them accordingly.  The history of slavery and racism in New Spain went hand in hand.  In the British colonies the story was similar.  The British felt superior to the cultures they found in the New World, although their exploitation of the Caribbean was much less extreme than that of the Spanish, who eradicated entire populations.  British settlers considered themselves more civilized than the natives, but in Virginia the colonists did not consider the Indians so inferior.  The natives were simply viewed as different people with different values, and at an obviously lower level of civilization.  In New England, on the other hand, Indians were viewed as animals without souls.  While intermarriage was encouraged in the South, it was not in the North.  As the legalisation of chattel slavery began in Massachusetts so did the doctrine of racial inferiority of Africans, to justify the practice of chattel slavery.  This doctrine spread throughout the British colonies, also to justify so undemocratic a practice.  The French never encouraged slavery in North America, but did practice it in the Caribbean.

So, essentially, racism by Europeans in the New World came with them, slavery following.  But both concepts existed in the Americas among the native peoples to start with, as they had existed in all cultures throughout history.