Confederate States of America vs Johnny Reb

Confederate States of America

name
  • An unrecognized nation existing from 1861–1865, consisting of the eleven Southern states who sought independence from the United States of America over the issue of slavery. 

Johnny Reb

noun
  • Synonym of Confederate: a citizen of the Confederate States of America, particularly a Confederate soldier. 

  • Synonym of Confederate States of America. 

How often have the words Confederate States of America and Johnny Reb occurred in a corpus of books? (source: Google Ngram Viewer )