Is it acceptable to blend some real history and fiction as Steinbeck has done? What passages ring true? Where do you find it lacking?
Many an author has blended history and fiction in order to record the experiences of the human heart which are indeed true. In fact, these experiences are the only real truth that does exist since historical facts and figures are often manipulated even by historians themselves, or later by politicos. Furthermore, it is the universal truths that matter, not so much the dates and incidents that precede or follow a historical event.