As History.com points out, though Christopher Columbus did not discover the New World, one of the impacts of his exploration was the opening of the North America to settlement and exploitation. Another impact was the devastation of the native population through disease, subjugation and environmental deterioration.
The first European to visit the North American coastline was Leif Erickson, who created a settlement in the Newfoundland area of Canada in the 11th century. Centuries later in 1492, Christopher Columbus, while searching for a route to the Far East, inadvertently explored some islands in the Caribbean and the South American coastline. The implications were profound for both the Old World and the New World. Europeans benefited from the raw materials brought back from the Americas. They also adopted nutritious foods from the Americas as part of their regular diets, including tomatoes, potatoes and corn.
According to Bio.com, the indigenous peoples of the Americas fared far worse. Though wheat from the Old World became an important food source and European horses helped entire cultures of Native Americans evolve on the great plains, far more people than were nourished by European food died off from imported diseases such as smallpox. Entire civilizations of indigenous populations were lost to epidemics of diseases for which they had no immunity.