Excerpt from the Oregon Blue Book:
“In 1902, the Oregon electorate overwhelmingly approved a ballot measure that created the initiative and referendum, a system of direct legislation by the people. In 1904, the electorate enacted the direct primary and, in 1908, the State Constitution was amended to include recall of public officials. These victories were the culmination of efforts by the Direct Legislation League, a group of political activists that progressive leader William S. U’Ren founded in 1898.
The initiative and referendum became known nationally as the “Oregon System,” and adoption of these popular legislative tools put Oregon in the vanguard of progressive and enlightened politics, allowing the people to propose new laws or change the State Constitution through a general election ballot measure….” (continue reading Blue Book entry)
Try these two websites for research on the Process of Initiative & Referendum:
1) Secretary of State, Initiative, Referendum and Referral webpage
2) Classroom Law Project: their Oregon Constitution / Initiative and Referendum Lesson Plan (always a place for excellent information, especially, if you are interested in teaching young people about the law, but also for anyone interested in learning).