An allusion is a reference to a person, idea, event, character, or another text. Often the reader will recognize the allusion but this is not always the case. The purpose of an allusion is to add meaning to a text by referring to some other text or event. The reference can be obvious or subtle.
The first allusion is the second sentence. King begins this sentence with "Five score years ago" and this is an allusion to Lincoln's "Gettysburg Address" which begins with "Four score and seven years ago." The remainder of King's second sentence overtly confirms this allusion to Lincoln and thereby establishes a historical bridge between the Emancipation Proclamation and the Civil Rights Movement.
Five score years ago, a great American, in whose symbolic shadow we stand today, signed the Emancipation Proclamation.
King also makes an allusion to the Declaration of Independence. "This note was a promise that all men, yes, black men as well as white men, would be guaranteed the unalienable rights of life, liberty, and the pursuit of happiness." The line from the Declaration of Independence is:
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
There are a few Biblical allusions. "No, no, we are not satisfied, and we will not be satisfied until justice rolls down like waters and righteousness like a mighty stream." This line is an allusion to the Book of Amos (from the Old Testament). The line from the Book of Amos is: "And justice shall be revealed like water, and righteousness like a mighty stream" (Amos 5:24).
In addition to the allusions, or references noted above there are others.
- King quotes the first verse of Samuel Francis Smith's popular patriotic hymn "America" (beginning "My Country ’Tis of Thee"), lyrics made to go with the tune of England's national anthem.
- King also is said to have borrowed from Prathia Hall's speech at the site of a burned-down church in Terrell County, Georgia in September 1962, in which she used the repeated phrase "I have a dream."
- In the second paragraph of King's speech, the sentence, "It came as a joyous daybreak to end the long night of their captivity" recalls verse 5 of Psalm 30, a song at the dedication of the house of David, in which weeping in the night gives birth to joy in the morning.
- Another Biblical allusion is that of Isaiah 40: 4-5,
the rough places will be made plain, and the crooked places will be made straight, and the glory of the Lord shall be revealed, and all flesh shall see it together.
as Dr. King paraphrases, saying that he has a dream
that every valley shall be exalted, every hill and mountain made low....
- And, allusions are made by King to the high points of various states such as New Hampshire, Pennsylvania, California, Colorado, Georgia, and Tennessee in reference to the reference of the book of Isaiah.