Americas vs United States

Americas

name
  • North America and South America taken together; that is, North America, Central America, and South America taken together. 

United States

name
  • The collection of individual states of the United States of America. 

  • Federal nation consisting of several states, actual, historical or hypothetical. 

  • Includes the land area, internal waters, territorial sea, and airspace of the United States. 

How often have the words Americas and United States occurred in a corpus of books? (source: Google Ngram Viewer )