I recommend you to read The Enemies of Christopher Columbus by Thomas A. Bowden. Here is an excerpt from Thomas Bowden's article, Columbus Day: The Cure for 9/11:
On one level, Columbus Day honors the explorer himself, for his many virtues. Columbus was a man of independent mind, who steadfastly pursued his bold plan for a westward voyage to the Indies despite powerful opposition--a man of courage, who set sail upon a trackless ocean with no assurance that he would ever reach land--a man of pride, who sought recognition and reward for his achievements.
We need not evade or excuse Columbus's flaws--his religious zealotry, his enslavement and oppression of natives--to recognize that he made history by finding new territory for a civilization that would soon show mankind how to overcome forever the age-old scourges of slavery, war, and forced religious conversion.
On a deeper level, therefore, Columbus Day celebrates the rational core of Western civilization, which flourished in the New World like a potbound plant liberated from its confining shell, demonstrating to the world what greatness is possible to man at his best. (Capitalism Magazine, 10/05/04.)