Saint Louis County vs USA

Saint Louis County

name
  • A county of Missouri, United States. County seat: Clayton. 

  • One of 87 counties in Minnesota, United States. County seat: Duluth. 

  • Synonym of Lake County, Minnesota, USA, in its former dimensions. 

USA

How often have the words Saint Louis County and USA occurred in a corpus of books? (source: Google Ngram Viewer )