Explorer who set in motion a series of events that would change the world forever. He made the North and South American continents available for exploration. Although some have argued that the Vikings actually arrived in the New World 400 years earlier, it was Columbus who provided the information for further exploration and settlement. As is the case with many influential people, his actions were not entirely benign - Columbus is also responsible for the spread of deadly infections to the indigenous people of the Americas, and marked the beginning of the end for many tribal groups who would fall to the invading European nations.