The North's naval superiority was most important in the U.S. Civil War because

  Peru.

Explanation:

  The Incan Empire was the largest empire in pre-Columbian America. It´s considered by most of the scholars to be the most developed culture in America. Its political, administrative and military center was located on what now is the city of Cusco.

  By the 1400s the empire was at its largest expansion including regions of Ecuador, Bolivia, Argentina, and Chile.

  I hope this answer helps you.