The commissioners, president, and county clerk (who serves as clerk of the board), hold the same offices ex officio on the separate governmental taxing body, the Cook County Forest Preserve District Board of Commissioners.

The first meeting of the new board took place December 4, 1871; they elected businessman and Civil War general Julius White of Evanston as their chairman.

Individuals who, before 1994, served as president of the Cook County Board of Commissioners included J. Frank Aldrich, Edward J. Brundage, Anton Cermak, George Dunne, Richard B. Ogilvie, Richard Phelan, Dan Ryan Jr. Charles C. P. Holden, and Seymour Simon.

The first county board chairman (a role which preceded the creation of the president position) was Julius White.

[5] Individuals who served as commissioners before the move to individual constituencies in 1994 included Charles Bernardini, George Marquis Bogue, Charles S. Bonk, Jerry Butler, Allan C. Carr, Carl R. Chindblom, John P. Daley, Danny K. Davis, Oscar Stanton De Priest, Marco Domico, Carl R. Hansen, Martin Emerich, Carter Harrison III, John Humphrey, John Jones, Walter J. LaBuy, Ted Lechowicz, Maria Pappas, Lillian Piotrowski, Herb Schumann, Harry H. Semrow, Francis Cornwall Sherman, Seymour Simon, Horace M. Singer, Bobbie L. Steele, Alanson Sweet, William Hale Thompson, and Jill Zwick.