Why are the rivers mentioned in the poem "The Negro Speaks of Rivers" significant?

The rivers mentioned--the Euphrates, the Congo, the Nile, and the Mississippi--are all connected to the history of "the Negro."

The rivers are metaphors for the history of the Negro; the three African rivers represent the ancient history of Africa in which there was freedom; the Mississippi represents slavery as many slaves were "sold down the river." Thus, Hughes connects the movement of the rivers with the continuum of black history.

In the second stanza, Hughes writes that his ancestors and a racial soul have done the things such as bathing in the Euphrates, building a hut near the Congo, and, throughout time, enduring--"My soul has grown deep like the rivers."

This lyrical poem imitates the flow of a river; moreover, there is a spiritual depth and knowledge acquired from the experiences of the world and the ancestry of the Negro that are carried by these ancient rivers. In the end, the speaker declares, "My soul has grown deep like the rivers."