While in Washington, D.C., Griffing maintained her dedication to women's rights and the cause of suffrage. In 1866 she helped found the American Equal Rights Association, whose purpose was to promote equality and suffrage for all people no matter their race or sex; she also served as its first vice-president. Griffing became the president of District of Columbia woman suffrage association in 1867, where she helped monitor guide suffrage activities in Washington, D.C. In 1869, along with Susan B. Anthony, Elizabeth Cady Stanton, and other prominent reformers, Griffing joined the National Woman Suffrage Association and acted as its corresponding secretary.