Seventy five years ago the American author John Steinbeck published what was to become his most-celebrated novel: The Grapes of Wrath. At the centre of the book is the story of the Joad Family whose farmland in Oklahoma, in America's mid-west, has turned to dust and whose farm has been repossessed. Faced with destitution they make the epic journey from Oklahoma to California in search of work and a better life. Along the way they are victims of prejudice and face exploitation at the hands of unscrupulous employers.
The book was an overnight success and for many became the parable of America's experience of the Great Depression. But it was also controversial with its critics seeing it as little more than thinly disguised left-wing propaganda.
The BBC's North America Editor, Mark Mardell has retraced the Joads' journey to explore the relevance of the book's themes in today’s America.