W.E. B. DuBois wrote about Mum Bett in his 1920 book of essays, Darkwater: Voices From Within the Veil.
"They came first, in earlier days, like foam flashing on dark, silent waters — bits of stern, dark womanhood here and there tossed almost carelessly aloft to the world's notice. First and naturally they assumed the panoply of the ancient African mother of men, strong and black, whose very nature beat back the wilderness of oppression and contempt. Such a one was that cousin of my grandmother, whom western Massachusetts remembers as "Mum Bett." Scarred for life by a blow received in defense of a sister, she ran away . . . and was the first slave, or one of the first, to be declared free under the Bill of Rights of 1780. The [lawyer who helped] free her, writes:
"Even in her humble station, she had, when occasion required it, an air of command which conferred a degree of dignity and gave her an ascendancy over those of her rank, which is very unusual in persons of any rank or color. Her determined and resolute character . . . was manifested in her conduct and deportment during her whole life. She claimed no distinction, but it was yielded to her from her superior experience, energy, skill, and sagacity. Having known this woman as familiarly as I knew either of my parents, I cannot believe in the moral or physical inferiority of the race to which she belonged. The degradation of the African must have been otherwise caused than by natural inferiority."
Quoted in Darkwater: Voices From Within the Veil, by W.E.B. DuBois (Harcourt, Brace, 1920.