Bluegrass State vs Kentucky

Bluegrass State

name
  • The official nickname for the state of Kentucky in the United States of America. 

Kentucky

name
  • A state of the United States. Capital: Frankfort; largest city: Louisville. Formally known as the Commonwealth of Kentucky, one of four such states known as Commonwealths. 

  • The Kentucky River, a river in the United States, a tributary of the Ohio River. 

  • A village on the Northern Tablelands, New South Wales, Australia. 

  • An unincorporated community in Munising Township, Michigan. 

  • University of Kentucky. 

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