Figure 2 | Direct Democracy Adoption Boomed in the Early 1900s
By 1920, 21 states—primarily in the West and Midwest—adopted ballot initiatives. Most of these adoptions were by legislative referral and a handful by constitutional convention. In some states, direct democracy was referred by the legislature but defeated by voters.
A timeline shows the number of states that adopted direct democracy measures in each decade. Of the twenty-one adoptions between 1898 and 1920, just six were by consitutional convention, and the rest by legislative referral. Three states in this time period had defeated attempts at legislative referral. A much smaller and more prolonged second wave of adoptions begins in 1956 with Alaska's adoption and ends with Mississippi in 1992.
