In Martin Luther king's I have a dream speech, the metaphor "cashing a check" means

They have to come get what the US has promised to give them

In another sign of the nation’s hyper-sensitivity around the issue of reparations for slavery, the architect of the forthcoming national memorial to Martin Luther King, Jr. revealed this week that King’s memorial will be censored to remove a key passage which has been used rhetorically in support of reparations.

The memorial to the nation’s leading civil rights figure, to be built on the National Mall in Washington, D. C., will have a crescent-shaped wall engraved with passages from King’s speeches and sermons.

Architect Ed Jackson, Jr. revealed, at an event to raise the final funds for the memorial, that they have chosen to remove a central line from the historic speech in which King announced, "We have come to cash this check - a check that will give us upon demand the riches of freedom and the security of justice."

King’s speech is built in part around the theme of coming to the nation’s capital to cash a check, which he explains consists of "a promise that all men would be guaranteed the inalienable rights of life, liberty, and the pursuit of happiness."

While some reparations supporters have used King’s words in arguing for financial compensation for the nation’s past, King uses the metaphor of a check only to speak of gaining intangible rights and privileges previously enjoyed only by white citizens.

In his remarks on the decision, Jackson asserted that the words weren’t removed in order to avoid fears today about compensation for slavery and discrimination. On the contrary, he said, the issue was that the passage would be unnecessarily divisive in a future in which race would be irrelevant:

For future generations, it should represent all Americans. We also felt that in the year 2050, this whole thing about black and white, won’t even exist.