[2] Blackford was active in the Episcopal church and the temperance movement, and in 1829 founded the Fredericksburg and Falmouth Female Auxiliary of the American Colonization Society.

[3] In 1834, she renamed the auxiliary as the Ladies' Society of Fredericksburg and Falmouth, for the Promotion of Female Education in Africa.

She raised funds, wrote pamphlets, and maintained an active correspondence with other anti-slavery activists, including her younger brother, a missionary in Liberia from 1937 until his death in 1843.

They had eight children in fifteen years,[10] and perhaps as a result, she experienced chronic severe back pain most of her adult life.

Five of her sons served in the Confederate States Army during the American Civil War,[10] which grieved her: “To see my sons arrayed against one part of their country,” she wrote in 1861, “is a sorrow that makes me feel the grave is the only place for me.” In 1892, her six living children gathered in Alexandria, Virginia, together for the first time since the war, to celebrate her ninetieth birthday with her.