Before the arrival of Columbus in 1492, unknown to a majority of the Eastern Hemisphere, he landed on Islands located in the middle of two huge continents now called North America and South America. They had a highly advanced civilizations that rivaled any in the world at that time. Thousands of smaller Nations and Tribes were united as one people, serving one God. Recent estimates suggest that population may have been 100-150 million people, from Alaska to Green Land North the to the tip of South America.