frontiersman vs immigrant

frontiersman

noun
  • A person who lives on the borders of a country, or in a wild and undeveloped area on the fringes of civilization. 

immigrant

noun
  • A non-native person who comes to a country from another country to permanently settle there. 

  • A plant or animal that establishes itself in an area where it previously did not exist. 

adj
  • Of or relating to immigrants or the act of immigrating. 

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