To understand the context of John Steinbeck's book, you need to know a bit about Steinbeck himself, and a little about economic conditions in 1930's America.
John Steinbeck was born in Salinas, California in 1902. Although his family was wealthy, he was interested in the lives of the farm laborers and spent time working with them. He used his experiences as material for his writing. He wrote a number of novels about poor people who worked on the land and dreamed of a better life, including The Grapes of Wrath, which is the heart-rending story of a family's struggle to escape the dust bowl of the West to reach California. Steinbeck was awarded the Nobel Prize for Literature in 1962, six years before his death in 1968.
On October 29 1929, millions of dollars were wiped out in an event that became known as the Wall Street Crash. It led to the Depression in America which crippled the country from 1930 - 1936. People lost their life savings when firms and banks went bust, and 12 - 15 million men and women - one third of America's population - were unemployed. There was then no dole to fall back on, so food was short and the unemployed in cities couldn't pay their rent. Some ended up in settlements called 'Hoovervilles' (after the US president of the time, Herbert C Hoover), in shanties made from old packing cases and corrugated iron. A song about an unemployed man meeting an old friend he has fought alongside in the First World War and asking him for a dime (the price of a cup of coffee) summed up the national mood.
Added to the man-made financial problems were natural ones. A series of droughts in southern mid-western states like Kansas, Oklahoma and Texas led to failed harvests and dried-up land. Farmers were forced to move off their land: they couldn't repay the bank-loans which had helped buy the farms and had to sell what they owned to pay their debts. Many economic migrants...