The American dream
One of the major themes in the novel is the idea that everyone can succeed. The people described in the novel all moved to the High Plains hoping to secure a good life for themselves and for their families. They were driven to the area by the desire to own a piece of land they could call it their own and they were shown their hard work could pay off. In the days when a bushed of grains was valued at 2 dollars, a farmer made more money that a movie star and could afford to live a comfortable life and buy everything he or she wanted for their families. When everything turned to dust and no one was making a profit any more, the vast majority of people still refused to leave their lands. They held onto the belief that things will eventually become better and they refused to give up on the life they knew. The people looked for signs in everything and harbored the idea that one day it will become better. The farmers who made a fortune during the years preceding the dust storms were the embodiment of the American Dream as they rose from nothing and ended up making more money that most people in the country and all because they worked hard and wished to better their lives.
The negative impact human kind can have on the natural environment
The book also analyzes the way humans affect nature in a negative way and thus it is one of the central themes in the book. The people who moved to the High Plains were told to farm as intensively as they want and the farmers were even encouraged to produce more and more with each passing year. While there were some people who tried to warn the farmers and the government officials about the dangers of extreme farming, they were ignored by the vast majority of population. When the prices dropped, the farmers reacted by expanding their production in an attempt to create more produce that could be sold and thus make profit. This only had a negative impact on the land as the natural grass holding the soil together disappeared. When the winds came, the topsoil was easily taken by the winds and thus what was left behind was a soil that easily absorbed water and easily let it evaporate when the heat waves came. Some tried to blame the weather for this catastrophe, claiming they had nothing to do with the destruction of the soil. they claimed the land will mend itself together in time and that it will become just like it was before. As time passed and more and more scientists took an interest in the matter, it became clear that the farmers were responsible for the tragedy affecting an entire nation.
Racism
The events described in the book take place in a time when the country was still affected by racism and the majority did not hesitate to express their racist ideas. The African-Americans were seen as being inferior to everyone and most cities had rules prohibiting the blacks from entering their towns or getting off the trains they were traveling with. If a black person did end up in the town, that person could have been arrested and put in prison or given other forms of punishment. The blacks were also the ones affected the most by the economic depression. While the unemployment rate among white people was high, the unemployment rate among blacks was more than double in comparison to their white counterparts and many claimed no black person will be hired until every white person has a job and is financially secure. Another group affected by racism were the Indians, driven away from their lands and perceived as being inferior. Some white communities were discriminated against as well and were denied entry into various states on the basis they were inferiors and good for nothing.
