Oak Park was made a township by the Cook County Board on November 17, 1902. The incorporation of Oak Park Township followed the formal incorporation of the Village of Oak Park by nearly a year. The governments have shared the same boundaries since that time.
The first slate of officers met on April 7, 1903 and included George Jenkins Bliss as Supervisor; James E. Tristram as both Township and Village Clerk; Thomas H. Gale as Collector; and Chris F. Hafner as Assessor. Oak Park Township residents also elected five Justices of the Peace and five Constables.
In 1936, a small group of electors put the Supervisor in charge of relief for the village poor. The state authorized Oak Park Township to levy an annual tax of assessed valuation for Poor Relief (now called General Assistance). By virtue of this duty, the Township Supervisor became the Township Treasurer.
The Township Board, comprised of four Trustees and the Supervisor, is the policy-making body of Oak Park Township. The Township Assessor and Collector did not (and still do not) serve on the Township Board.
Oak Park Township has grown over the years since its inception in 1902 and currently serves a population of over 50,000. In addition to continuing to provide financial relief to needy area residents, Oak Park Township funds and administers many programs for area seniors and youth.