How did the arrival of European explorers change North America

European explorers brought diseases, crops, and new animals to North America.
After Christopher Columbus discovered North America, he brought back information of the Natives living there. In years to come, other explorers would help establish the Columbian Exchange. In this exchange, diseases brought to the Americas killed upwards of 90% of all of the Native Americans there. Since Natives were used for labor, this led to a gradual shift in using African slaves instead. New crops changed the landscape of North America and therefore the economy saw a dramatic increase. New domestic animals changed the landscape as well, especially introduction of the horse. Natives and conquistadors alike used horses, which emphasized long distance trade routes across the continent.

What does that mean mon