as of May 2009, in 23 states and one territory: Alaska, Arizona, Arkansas, California, Colorado, Idaho, Maine, Maryland, Massachusetts, Michigan, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Ohio, Oklahoma, Oregon, South Dakota, Utah, Washington, Wisconsin, Wyoming and the U.S. Virgin Islands. The popular referendum was first introduced in the United States by South Dakota in 1898, and first used in the United States in 1906, in Oregon, two years after the initiative was used (in 1904, also in Oregon). See also Initiative Recall election Legislative referral References Direct democracy Referendums