An example of personification in Martin Luther King's speech is, "I have a dream that one day this nation will rise up and live out the true meaning of its creed." Personification gives human qualities to something that is not human.
The definition of personification is the attribution of human nature or character to animals, inanimate objects, or abstract notions, especially as rhetorical figures. The idea of personification is to create a more relatable situation by giving life-like qualities to nonliving objects.
Martin Luther King uses personification in his speech to exemplify the need for change. In the example of "I have a dream that one day this nation will rise up and live out the true meaning of its creed," King is personifying the United States by giving it human qualities. The United States is simply a plot of land; it cannot physically or mentally rise up; however, the people who call themselves United States citizens can do this. King is referring to the country as whole, meaning the people who live in it.
King also uses personification when he says, "America has given the Negro people a bad check." America cannot physically give a bad check, whether King is saying it metaphorically or not.