The son of Dutch-American Cornelius P. Van Ness (1782–1852), who served as Governor of Vermont, and Rhoda Savage (d. 1834), his first wife.

[4] Van Ness tried in vain to have California Governor J. Neely Johnson send state militia forces into the city to stop the executions.

Van Ness would leave office in July under the terms of the Consolidation Act (passed by the state legislature on April 29, 1856), which provided for the merger of the city and county governments into one unit.

Until then, the mayor would be known as the "President of the Board of Supervisors" In 1860, he moved to San Luis Obispo County to practice law and, in 1871, became a state senator.

[10] Van Ness Avenue is named in his honor, as well as a street in Santa Cruz, Los Angeles and Fresno.