It is obvious today that America has defaulted on this promissory note insofar as her citizens of color are concerned. Instead of honoring this sacred obligation, America has given the Negro people a bad check, a check which has come back marked “insufficient funds.”

In this quote, Dr. King describes the “check” or “promissory note” written to all American citizens by the Constitution and Declaration of Independence and argues that the United States has not kept its promises to Black Americans. Though they have been freed from the institution of slavery, they continue to exist on a “lonely island of poverty,” moving only “from a smaller ghetto to a larger one,” and suffer many other injustices. 

No, no, we are not satisfied, and we will not be satisfied until justice rolls down like waters and righteousness like a mighty stream.

In this descriptive biblical allusion to Amos 5:24, King asserts that African Americans will not cease fighting for equal rights until the freedom that has been promised to them is theirs. The images of a flood and river imply the extent of justice that is necessary in the United States: only a “mighty stream” of wrong made right will satisfy them. 

This is our hope. This is the faith that I go back to the South with. With this faith we will be able to hew out of the mountain of despair a stone of hope. With this faith we will be able to transform the jangling discords of our nation into a beautiful symphony of brotherhood. With this faith we will be able to work together, to pray together, to struggle together, to go to jail together, to stand up for freedom together, knowing that we will be free one day. 

After describing his dream for the United States, King assures his listeners that it is the African American community’s hope for a better country that will allow them to continue fighting for equal rights. Just as King’s civil rights campaign is anchored not in violence but in peace, he draws his motivation to continue fighting not from bitterness but from hope for his country.