What impact did Christopher Columbus have upon the New World?

Columbus had a profound impact on the New World.  Even though he thought that he had found Asia, Columbus's voyage still brought Spain a great deal of wealth.  Thousands of young Spaniards dreamed of going to America and striking it rich either in the spice trade or in gold.  With the exception of sugar production, the spice trade never really materialized in America the way the Spaniards had hoped, but thousands of Spaniards grew rich on the gold trade.  Of course, this was often done by subjugating the indigenous people who lived in the New World.  The arrival of Columbus marked the end of many native cultures in the New World.  European diseases such as smallpox, typhoid, and malaria wiped out over ninety percent of the indigenous people who lived in the New World in the two hundred years after Columbus's voyages.  Also, European livestock, such as hogs, escaped their owners and quickly became feral.  These hogs ate many crops Native Americans needed for survival and are still a nuisance in the United States today.  The horses that escaped from their pens were domesticated by the Plains Indians; the horse was soon used as a type of wealth.  It could be used on the battlefield as well as the buffalo hunt.  Columbus's arrival in the New World brought mainly bad things for the natives who already lived there, but the horse was the one positive thing brought from Europe to the New World.