Gumby started his scrapbook collection in 1901 at the age of sixteen. After moving to New York Gumby began to seriously collect the materials which makes up his collection. In 1910 he started the process of gathering the material he had assembled into scrapbooks, and forty years later, in 1950, he presented this acclaimed collection to the Columbia University Libraries. Materials consist of newspaper clippings, periodical extracts, photos, pamphlets, playbills, letters, manuscripts, and materials Gumby gathered personally from subjects such as Josephine Baker, Joe Louis, Paul Robeson, and many other political, cultural and sports figures. Each scrapbook is devoted to one subject, either a person, an organization or a topic.

A strength of the collection is the individual scrapbooks on noted people, such as W.E.B. DuBois, Langston Hughes, Ralph Bunche, Frederick Douglass, Marcus Garvey, Jackie Robinson, Booker T. Washington and many other African Americans. Topics include Lynchings and Race Riots; Social Equality; the Negro (Gumby's term) as a Soldier; Harlem; the Negro and Communism; the Negro in Bondage; the Negro in Politics and more.