[1] For a single year during (1855-56) this time, Chicago briefly had an appointed Chief of Police position that co-headed the department alongside the City Marshall.

[1][2] Samuel Nolan was the first African-American individual to serve as head of the police department in an interim capacity, doing so from late–1979 until January 1980.

[3][4] On November 8, 2019, Mayor Lori Lightfoot appointed retired Los Angeles police chief Charlie Beck as the city's interim superintendent.

[6] He was preceded by Garry F. McCarthy, former director of the Newark, New Jersey, Police Department, as superintendent; this was approved by the city council on June 8, 2011.

Mayor Richard M. Daley appointed Cline's predecessor, Terry Hillard, on an interim basis.

While no mayor was serving at the time he was High Constable, John H. Kinzie was Town President ^B The position of "General Superintendent of Police" ceased to be the head of the Chicago Police Department prior to the end of O'Connor's tenure, which was December 29, 1964