The modern administrative state, as measured by the number of agencies, their budgets and staffing, and the number of regulations they issue, has grown significantly over the last hundred years. This essay reviews the origins of the administrative state and identifies four milestone efforts to hold it accountable to the American people: passage of the Administrative Procedure Act in 1946, the economic deregulation of the 1970s and 1980s, requirements for ex ante regulatory impact analysis, and the establishment of White House review. These milestones reflect bipartisan consensus on appropriate constraints on executive rulemaking, but they have not succeeded in stemming the debate over the proper role for administrative agencies and the regulations they issue. New milestones may include judicial interpretations, legislative actions, and extensions to executive oversight.