Due to the exclusion of women from the American Anti-Slavery Society, in 1833 Forten, with her mother Charlotte and sisters Sarah and Harriet, co-founded the Philadelphia Female Anti-Slavery Society with ten other women. The goal of this new society was to include women in the activism being done for the abolition of slavery, and "to elevate the people of color from their present degraded situation to the full enjoyment of their rights and to increased usefulness in society." (Brown, 145)  Forten often served as recording secretary or treasurer of the Society, as well as helping to draw up its organizational charter and serving on its educational committee. She offered the Society's last resolution, which praised the post-civil war amendments as a success for the anti-slavery cause. The Society distinguished itself at the time as the first of its kind in the United States to be interacial. Although the Society was predominantly white, historian Janice Sumler-Lewis claims the efforts of the Forten women in its key offices enabled it to reflect a black abolitionist perspective that oftentimes was more militant.
Forten toured and gave speeches in favor of women's suffrage, as well as helping petition drives for the cause. She also worked as a teacher, teaching at a school run by Sarah Mapps Douglass in the 1840s, and opening her own school in 1850.
- Alexander, Leslie. Encyclopedia of African American History, Volume 1 ABC-CLIO (2010) p.1045
- "Margaretta Forten" on Find a Grave
- Smith, Jessie Carney and Wynn, Linda T. Freedom Facts and Firsts: 400 Years of the African American Civil Rights Experience Visible Ink Press, 2009. p.242
- Christian, Charles Melvin and Bennett, Sari J. Black Saga: The African American Experience : a Chronology Basic Civitas Books, 1998. p.1183
- Brown, Ira V. "Cradle of Feminism: The Philadelphia Female Anti-Slavery Society, 1833-1840." The Pennsylvania Magazine of History and Biography, vol. 102, no. 2 (1978), 143–66
- Gordon, Ann Dexter and Collier-Thomas, Betty. African American Women and the Vote, 1837-1965 University of Massachusetts Press, 1997. p.33
- Hine, Darlene Clark (1998). A Shining Thread of Hope: The History of Black Women in America. New York: Broadway Books. pp. 38. ISBN 0-7679-0110-X.
- Sumler-Lewis, Janice (Winter 1981–1982). "The Forten-Purvis Women of Philadelphia and the American Anti-Slavery Crusade". Journal of Negro History. 66 (4): 281–288. JSTOR 2717236.
- Fels, Anna. Necessary Dreams: Ambition in Women's Changing Lives Random House Digital, 2005. p.173