We are very lucky. The Grapes of Wrath gives us a window into the lives of migrant worker families escaping the Dust Bowl in late 1930s America. Steinbeck creates fictional characters and sets them against the backdrop of an important chapter in American history. Not only to we get to know the Joads well, but we also get to know the history of the Dust Bowl and of the migrant worker communities very well.
The Joads seem to undergo an odyssey in their quest for peace and happiness. While it is arguable as to whether they ever achieve this peace, the novel vividly details the quest and all of the gruesome obstacles that pop up along the way.