On May 13, 1971, in the Gilman News article titled "BSO Formed," Clarence Young '73 describes the formation of Gilman's first affinity group. He writes, "In the midst of growing concern among black students of Gilman School for some tangible reinforcements of their cultural identity, the consensus was that a representative organization of some sort be established. When the Black Student Organization was first conceived last spring , the objectives and goals were varied as well as vague; however, as a result of several meetings among themselves, the students brought up a few recommendations before Mr. Finney. At the time, the group possessed diverging views regarding different aspects of the school and school life. However, the need for such reinforcement and awareness served to unite the group. A meeting of parents and students, as well as Mr. Campbell and Mr. Finney, proved to be most revealing. It was felt that an organization of black students was both practical and necessary."
With the idea approved in the spring of 1970, the Black Student Organization first met in the fall of 1970 with plans to coordinate a service project. According to a May 1972 issue of The Gilman News, one of the groups' first significant accomplishments was the establishment of a tutoring club.