This paper examines the adoption of state electricity regulation around the beginning of the 20th century. I model this decision as a hazard rate to determine what influenced the adoption of state regulation. I find that adoption is positively correlated with capacity shortages, greater wealth and lower residential electricity penetration rates. These results suggest that state regulation responded to regulatory inefficiencies and residential consumer interests. In addition, adoption rates were higher in states that had a strong industrial and coal mining presence. These results are consistent with the interest group and contracting theories of regulation.