The 100th anniversary of Wisconsin statehood was commemorated by a 3-cent purple stamp issued on May 29, 1948. The design pictures the State Capitol to the right of a scroll showing an outline map of the state and the words "Wisconsin Centennial 1848-1948." Wisconsin became a territory in 1836, after having been part of the Northwest, Illinois, and Michigan territories. A successful referendum in 1846 led to statehood. By that time, the population had grown to more than 150,000, well above the minimum of 60,000 for statehood established by the Ordinance of 1787 for the Northwest Territory.