
In 1969, Williams became the first African-American elected to the San Diego City Council as a representative for District IV. He later became county supervisor in 1982. As County Supervisor, Williams was president of the California State Association of Counties in 1993, and he was on the board of directors for the National Association of Counties. Both these associations serve to represent county governments before the state and federal legislatures.
During Williams' years in the City Council, he helped initiate the Southeast Economic Development

In addition to (re)development projects, Williams created the Human Relations Commission and the Hate Crimes Registry to tackle racial and religious tensions. He fought for state constitutional reform as a member of the California Constitutional Revision Committee, and helped change the county charter to increase government accountability. Williams' Prevention Policy sought to create long-term solutions for issues such as crime, drugs, welfare, and health concerns. During this time, Williams also taught public policy classes part-time at San Diego State University.
Although Williams worked as a councilman, he was also active with the Metropolitan Transit Development Board (MTDB). In 1976, he began his long tenure with the MTDB, and in 1994 was appointed chairman of the Transit System's board of directors. Williams had always supported the use of public transportation as a means to connect and revitalize San Diego's older neighborhoods, rather than expand into undeveloped areas. He believed the creation of the San Diego Trolley was the best way to achieve this goal. He was also the chairman of the Services Authority for Freeway Emergencies (SAFE), and was responsible for freeway call boxes. He retired from City Council in 1995, and the MTDB in 2005.
