This paper provides an overview of the public labor exchange system in the United States, how it came to be, and where it is going. The paper begins by offering a brief history of the development of the U.S. Employment Service, emphasizing the federal-state partnership that has evolved over time and highlighting the differing priorities Congress has placed on the services funded under Wagner-Peyser Act. It then examines the ways workers search for jobs and employers recruit employees. It also shows the role the ES plays in this job matching process. The complementarity between ES services and the broader workforce development system is then examined. Systems for ES performance measurement and the results of impact evaluations of ES services are then reviewed. The paper concludes with a summary and list of challenges facing the ES.