He was one of several youth activists involved in the latter actions, along with John Lewis, William Barbee, Paul Brooks, Charles Butler, Allen Cason, Catherine Burks, and Lucretia Collins.
[3][4] Soon after arriving in Tennessee, Harbour joined the Student Central Committee of the Nashville Christian Leadership Council at the behest of John Lewis,[3] a fellow activist and close friend (the two had met on a bus ride to a rally in Rock Hill, South Carolina).
[6] Out of a large number of volunteers, Harbour was one of only a few selected to take part in the first Freedom Rides; other participants included seven blacks — John Lewis, William Barbee, Paul Brooks, Charles Butler, Allen Cason Jr., Catherine Burks and Lucretia Collins —, and two whites — James Zwerg and Salynn McCollum.
[6] While Harbour’s difficulties were far from unique, the pattern of "brutality and jail terms" which he and his fellow activists encountered not only strengthened the Freedom Riders' resolve, but also increased publicity and motivated others to join them.
After a short stint as a Georgia school teacher,[3][7] and a period of involvement in the "War on Poverty" under President Johnson,[4] he became a federal civil servant "specializing in U.S. Army base closings".