According to Thom Steinbeck, the author's oldest son, the reason for the trip was that Steinbeck knew he was dying and wanted to see his country one last time. The younger Steinbeck has said he was surprised that his stepmother allowed his father to make the trip; his heart condition meant he could have died at any time. A new introduction to the 50th anniversary edition of the book cautioned readers that "it would be a mistake to take this travelogue too literally, as Steinbeck was at heart a novelist."