In what ways are the early (pre - 1600) histories of mexican and the present day american south-west understood differently now that the united states is being so substantially affected by mexican and latin american immigration and culture?

Pre-1600 the borders that once existed were among tribes and the famed Aztec culture. These were during times of aggressive imperialism and the policy of a lot of European countries at the time were to just gather land and gain more power through resources. Borders will always exist, but people will always be people. Proud of where they are from, but forget that they are people first. Our cultures are nothing more than the lands we are on and how we use them. In the present state, the culture remains, unchanged, there has always been a flux of people to new and old lands but it is only told through the eyes of the person's perspective. Back then borders were not as discrete, now it is. We as a society choose to not view differences, but it is acknowledging them is what makes us unique.