Fargo vs Plattsmouth

Fargo

name

  • The largest city in North Dakota, United States, and county seat of Cass County. 

  • A surname. 

Plattsmouth

name

  • A city, the county seat of Cass County, Nebraska, United States. 

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