Free State vs Old Line State

Free State

name
  • A nickname for Maryland. 

  • The Irish Free State. 

  • A province of South Africa. Capital: Bloemfontein, formerly Orange Free State. 

  • Irish republican term for the present-day Republic of Ireland. 

Old Line State

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

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