In 1975 Hilliard began his political career when he won a seat in the Alabama state legislature representing a Birmingham district. Elected to the state senate in 1980, Hilliard fought for legislation that would benefit the urban poor. During his time in the state senate, he became chairman of the Judiciary and Commerce, Transportation, and Utility Committees. He also joined the boards of trustees at Miles College and the Tuskegee Institute.
Throughout his ten years in Congress, Hilliard focused on economic issues, such as preventing the closure of the Tuscaloosa airport and reestablishing the Gees Bend Ferry. He also fought for the expansion of Alabama"s military installations. He also continued to support legislation that would help Alabama’s urban poor. He called for a Southern Rural Development Commission, modeled after the Appalachian Regional Commission to assist economic development in rural communities in ten southern states.