He was appointed to the Quebec Superior Court for the District of Montreal on September 24, 2004.

In July 1790 he was appointed justice of the peace for the District of Trois-Rivières.

In 1964 he became the first African-American to be appointed the United States district court for the District of Columbia.

He was the first African American appointed to the Federal District court for the District of Massachusetts.

In 1881, he was appointed Recorder of Deeds for the District of Columbia.

In 1990 he was appointed to the federal Court of Appeals for the District of Columbia.

In 1889, he was appointed a Judge of the Superior Court for the District of Bedford.

Also in 1909 Campbell was appointed as a circuit court judge for the 5th District, serving until 1911.

He was subsequently appointed engineer for the District of Otago.

He was appointed as the United States Attorney for the District of New Hampshire from 1845 to 1847.