One can only admire the Joads for their dogged persistence in doing whatever they can to find a better life for themselves. Forced to leave their Oklahoma farm after it was repossessed, the Joads have loaded up their few belongings to head out West to California in the hope of finding work. On the way there they encounter numerous hardships. After experiencing the deaths of Grandpa and Grandma Joad, they find themselves herded into an overcrowded camp jam-packed full of other desperate migrants.
Even when the Joads finally reach California, their troubles are far from over. There's an over-supply of workers, and so wages are low and exploitation high. There's a chance to escape from exploitation, but only by staying at a migrant worker camp run by the Federal government. It's better than nothing, but it's still far from ideal.
Tom Joad experiences more hardships than anyone else in the family. This is because he's become politically aware and engages in activity against the exploitative practices of employers. Inevitably, this makes him a target for employers, who regard him as a trouble-maker. Eventually, Tom kills a man after an industrial dispute turns violent, and he's forced to flee. The road ahead looks long and hard for Tom, especially as he's vowed to keep on fighting for workers's rights.
The rest of his family also have a hard time ahead of them. Still slaving away all day for an absolute pittance, we leave them as they find shelter in a barn from a devastating storm that has caused widespread flooding in the area. The Joads may have overcome more hardship than most people would experience in a lifetime, but Steinbeck wants us to realize that there's more to come for them and countless others like them in the America of the Great Depression.