Field was a justice from 1863-97, the second longest tenure of any associate justice. Although named to the court by Lincoln, Field played an important role in turning the focus of the court away from black rights and toward protecting big business. He dissented in Munn v Illinois, allowing states to regulate railroads within their borders. He opposed the graduated income tax, anti-trust laws, and the Interstate Commerce Commission. He also sided with the majority in Plessy v. Ferguson.