[1] Cassey was a member of the group of elite African Americans who founded the Gilbert Lyceum, Philadelphia's first co-ed literary society.
[2][3][4] Amy Matilda Williams Cassey was born free into a prominent African American family, in New York City, to Sarah and Peter Williams, Jr.[5] Her father founded and was the pastor of St. Phillips Black Episcopal Church in lower Manhattan.
Cassey was active in the Philadelphia Female Anti-Slavery Society which focused on providing access to opportunities for education, moral reform, and vocational training for the free black community living in Philadelphia.
The albums circulated within a community of free people and abolitionists from Boston to Baltimore, who in turn contributed their own work.
[8] In 1853, Cassey brought a successful suit against the management of a Boston theater when she was wrongfully ejected.