Why did the south become heavily dependent upon cotton?

Because of the high demands from Europe.

Explanation:

All demands of cotton inserted the U.S. in the global economy. Its profitability mainly was due to slavery, cheap labor. Mississippi was the epicenter of a large economy back then, it became an important region from national economy.

the anwer to

this question is false the spnaish had more than enough reinforcments and soldiders to defeat the azatecs becuase the azatecs did not have the advanced technolgy the spanish did