With compassion and empathy we can overcome indifference, intolerance, and injustice. Without it our society cannot function properly.

I'm not sure what exactly your question is here but I think this might help. The beauty of The Grapes of Wrath is that the experiences of the Joads speak for the experiences of thousands of other families traveling west in search of a better life. Such commonality of experience exists in the historical content that is laid out at the beginning of the novel, and also occurs within the novel's architecture itself. Steinbeck's novel transitions between chapters that detail the lives of the Joads and the chapters that deal with migrants more generally. It is in these chapters, which discuss broader currents and trends, that the commonality of experience truly shines through. These portions of the narrative are especially effective in communicating this theme because they always preface the more detailed, Joad-oriented chapters; in essence, they set the stage for the particular aspects of the Joads' lives. In this way, the commonality of experience adds gravity and importance to Steinbeck's The Grapes of Wrath, assuring it a place among great and resonant works of American literature.