In the summer of 1964, Sheila travelled to Mississippi as part of the “Freedom Summer” efforts to help organize blacks and challenge the restrictions that prohibited them from voting.
She wanted to spend the full summer there, but due to her parents’ concern, was limited to a shorter trip, probably under the auspices of SNCC.
She spent her time there traveling to small towns in the midst of intense racial tension. On June 21, three other young white northern organizers were murdered by a local posse.
During this time, Sheila travelled with the Deacons for Defense and Justice, an armed political black self-defence group.
On a few occasions, Sheila mentioned a story from this time of driving around back roads in rural Mississippi in a car full of Deacons, young black men carrying guns, and being followed by another car, filled with armed white men; the Deacons urged Sheila to duck her head down, for fear that if the other car had noticed that a white girl was riding with them, it might have resulted in a confrontation and shoot-out.