Significance of the Spanish Empire
First, because of the Spanish Empire, there was a new wealth of knowledge going back to Europe about the New World. This also triggered indigenous intellectual revolution as groups absorbed and then refined new technology to meet their needs.
The Spanish Empire was very durable and influencial from 1492 to the 1840s in the lower half of what is now the United States and the Pacific coast. However, there were many environmental changes brought upon by the Columbian Exchange, along with new breeds of livestock, pests, and new DNA combinations from the conquistadors mating with the natives.
Because of the new DNA combinations from the conquistadors mating with the natives, there are new bi-and tri-racial populations. The Spanish also help to perfect the Trans-Atlantic slave routes from Africa, because of the need for even more mine workers after the discovery of gold, and to create European expectations that slave labor, whether Indian or African, would be fundamental and beneficial to colonial society and its success.
During this time, there was a 600% inflation rate in Europe which made Spain the most powerful nation in the 16th century. Every other European nation of means wanted to score rich empires in the Americas.