Repetition in "The Negro Speaks of Rivers"

I thoroughly enjoyed the poem "The Negro Speaks of Rivers" by Langston Hughes, but I could not figure out what it was about the poem that drew me in. I read it and re-read it over and over trying to figure out what it was about this poem when finally it clicked with me. In this short poem Hughes repeats what he says at the beginning of the poem at the end and for me this use of repetition works very well to emphasize his point and tie the whole poem together. Also when I read the poem I noticed that it has a certain flow to it. The words come out of my mouth in a rhythm that reminds me of the flow of water in a river. I was also drawn in by how strongly such a short poem could affect me. Each word in the poem has a meaning and a purpose. There is not a single unnecessary word in it. After reading this poem I now want to read more of his works. In my own work I often have unnecessary words and sentences, and I think that I could learn a bit about the importance of each word in a story from Hughes.