The aztecs conquered or influenced their neighbors by beating their asses and being scary, dodo. What the fuck kind of question is that?
But they knew the world was big, they had trade networks measured in the thousands of miles.

But the real mystery is the Caral site in Peru, which hit mainstream archaeology a few years ago and has construction dating back to the First Interregnum in Egypt. Yes, really.
https://en.wikipedia.org/wiki/Caral