Leigh became the assistant to Bayard Rustin, when Rustin was organizing the 1963 March On Washington. After the March, Leigh joined the Student Nonviolent Coordinating Committee in Atlanta. In SNCC he worked at times with Communications Director, Julian Bond, and manned the WATS-line. WATS was SNCC's main means of communicating with the activists in the hamlets of the South. WATS saved money and had the advantage of avoiding putting calls through the local telephone operators, who could listen to the calls and were often very friendly with the constabulary and the Ku Klux Klan. Leigh could type 120 words a minute and his efficiency and competence made him invaluable to the organization.