Robert Hayden was born on August 4, 1913 and died on February 25, 1980. He was an American poet, essayist, and educator. He served as Consultant in Poetry to the Library of Congress from 1976 to 1978, a role today known as US Poet Laureate. He was the first African-American writer to hold the office.
Robert Hayden was born in Detroit, Michigan, son of Ruth and Asa Sheffey. The couple separated before his birth. He was taken in by a foster family next door, Sue Ellen Westerfield and William Hayden, and grew up in a Detroit ghetto nicknamed "Paradise Valley". The Haydens' eternally belligerent marriage, coupled with Ruth Sheffey’s competition for her son's affections, made for a traumatic childhood. Witnessing fights and suffering beatings, Hayden lived in a house troubled with chronic anger. His childhood traumas resulted in debilitating bouts of depression that he later called "my dark nights of the soul".
Before answering the question, I would like to mention what we call free verse poetry. It is poetry that is free from limitations of regular meter or rhythm, and does not rhyme with fixed forms. Such poems are without rhythm and rhyme schemes, do not follow regular rhyme scheme rules, yet still provide artistic expression.
We can conclude that the present poem is written in free verse because:
There is no rhyme scheme.
The lines are unequal in length.
The other options present limitations or patterns which are the opposite characteristics of free verse.