Because her role at these colleges included coordinating religious activities, she became involved with numerous organizations in the Student Christian Movement in the South.
Through this work, Fairfax became close friends with the influential civil rights leader and feminist Nelle Morton, then the executive secretary of the Fellowship.
After World War II, from 1946 to 1948, Fairfax served as a program director for the American Friends Service Committee, a Quaker organization.
[7]: 6 In this capacity she made important contributions to the civil rights movement in the South, as she continued to organize and assist black families confronted with the effects of early school desegregation.
She drove Legal Defense and Educational Fund (LDF) attorneys through rural Mississippi to meet with parents to discuss their decision about whether to send their children to white schools with a high risk of hostility.
[8] In addition, Fairfax personally (with Derrick Bell) escorted 6-year-old Debra Lewis to her first day of integrating the all-white Carthage Elementary School in rural Leake County, MS.
Interviewed by the Christian Science Monitor, Fairfax once said, "Someone had to break the pattern, and very often the civil rights revolution was initiated by the most vulnerable black persons.
[9]) In 1987, the two sisters established the endowment for the Dan and Betty Inez Fairfax Memorial Fund to expand educational opportunities for African American and Latinx students.
Writing in "Black Philanthropy: Its Heritage and Its Future" (1995), she admitted that she herself at first adopted the widespread misconception that "philanthropists were white people with inherited wealth or who made big deals in their investments or in their industrial work, like the Carnegies and the Rockefellers.