Confederacy vs Confederation

Confederacy

name
  • The Confederate States of America, the collection of American states that seceded from the United States in 1860–61, and fought against the Union in the American Civil War. 

Confederation

name
  • In Canada, the date of Confederation; 1 July 1867. 

  • In Canada, the federal union of provinces and territories which formed Canada, beginning with New Brunswick, Nova Scotia, Ontario, and Quebec, and later including all the others. 

  • In Newfoundland, the political union of Newfoundland with Canada. 

  • In Newfoundland, the date of Confederation; 31 March 1949. 

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