The title of the novel is taken from The Battle Hymn of the Republic by Julia Ward Howe in 1861, and also connect to Biblical verses in Isaiah 63 and Revelations 14:19-20. Both refer to God's judgment and restoration of righteousness in the face of oppression and wrongdoing.

The Joads and other farming families were thrown off of their land and needed gainful employment, which they often could not find because of the greedy landowners who hire migrant workers for less than a living wage. The title hearkens back to the powerful imagery in the hymn and the Bible of God destroying the oppressors of the world. The novel works as a plea to God to grant justice to the exploited and disenfranchised families and workers like the Joads.

ALLUSION

HOW IT ENHANCES MEANING

The Grapes of Wrath