He earliest evidence of monumental architecture in the valley of mexico was discovered at:

Before the European arrival,  the civilization of Mexico was established and developed in the center and southern provinces of Central America which also known as Mesoamerica. The valley of Mexico contained numerous large paleo-lakes which also known as Lake Texcoco, it is surrounded by thick forest. 

lincoln declared that slavery should not be allowed to spread into the new states, and of course this angered the south at the time.

norsemen from northern countries had made earlier journeys