When he left Stanford University in 1925 without completing a degree, Steinbeck decided to become a freelance writer, which meant that he would not be tied to a single employer but would write articles and stories which he would submit to different publishers. He would, of course, only be reimbursed once his work was accepted.

This was a failed venture and Steinbeck survived by doing odd jobs in New York as a construction worker and a newspaper reporter. Displeased, he returned to California in 1928 and found work as a caretaker and tour guide in Lake Tahoe.

His career as a writer only commenced in 1929, with the publication of his first novel, Cup of Gold. The book had limited success and after two more novels, he finally achieved real success in 1935 with the novel, Tortilla Flat. This gave him a head start and established him as a writer. He soon followed this success with In Dubious Battle (1936), Of Mice and Men (1937) and The Long Valley (1938), which featured a collection of short stories. His most famous  work, The Grapes of Wrath, was published in 1939. At one time, the novel sold more than 10 000 copies a week and earned him the Pulitzer Prize in 1940.

Steinbeck was awarded the Nobel Prize for Literature in 1962 for his outstanding contribution to literature and "his realistic and imaginative writings, combining as they do sympathetic humour and keen social perception."