I haven’t read the book tho I have seen the movie a few times. It was pretty good but it is always a good idea to keep in mind that Steinbeck was a commie.
The Soviets thought it would be a good film to show in the USSR, because it showed economic disaster in the United States. Too bad they had to stop doing that when the Soviet citizens realized that even the poorest of the poor in the United States had cars and trucks.
Steinbeck’s communism glared through that book like Ayn Rand’s materialism glares through “Atlas Shrugged.” It is really a very ugly book. I love literature, but Grapes of Wrath was really a barely concealed manifesto. Nothing about America worked right, not at all.