What are the lasting effects of Spanish exploration on both the New World and the Old World?

First of all trade routes were opened, thus introducing new cultures into both areas. Of course, this totally changed the diet of people, which among the other things extended the life of people. On the other side, Europeans brought with them diseases that shortened the population of Americas, which eventually led to decline of the population among Native Americas.

Explanation:

During the Age of Exploration maritime trade expanded to unbelievable heights. Enlarged exchange of products led to the establishment of trade connection with New and Old World. Still, there were also bad sides of this exchange. Slave trade became integral part of the exchanging process, while on the other side Europeans brought with them certain diseases, among which deadliest were smallpox.

what the first or next guy says

no statements but ok.

the statement that best describes the idea of manifest destiny that was used in the 19th century would be that "it was fate that the united states would continue to  expand westward," since people thought the us was "destined" to do so.