Steinbeck i brev til forleggeren sin om hvordan og hvorfor han vil ha the Battle Hymn på coveret til Vredens Druer:
The facist crowd will try to sabotage this book because it is revolutionary. They will try to give it the communist angle. However, the Battle Hymn is American and so intensely so. Further, every American child learns it and forget the words. So if both words and music are there the book is keyed into the American scene right from the beginning. (1/10/39).