The records are organized into two major series. Series I contains records created by the companies that formed Ohio Edison prior to and after its merger with Ohio Public Service Company from 1869 to 1964. Series II includes records from the companies that formed Ohio Public Service before the 1950 merger with Ohio Edison to form the OEC. Within each series the subsidiary companies are listed in alphabetical order. The collection contains a wide range of records from approximately two hundred companies. Minute books, internal reports, Public Utilities Commission of Ohio (PUCO) reports, Ohio Tax Commission reports, Interstate Commerce Commission reports, technical drawings and photographs are included. Of special interest is material relating to a 1935 U.S. Securities and Exchange Commission (SEC) case and 1940-1942 Federal Power Commission (FPC) case. In both cases the collection contains internal correspondence and background material used in preparing the case. Other material of special interests include various reports to the SEC covering mergers between Ohio Public Service and Ohio Edison and minute books dating into the 19th century which provide glimpses of business methods used during that era. For a researcher interested in street car and interurban development, the collection holds numerous possibilities. In particular the Stark Electric Railroad material contains PUCO annual and accident reports, timetables, motormen reports, and financial records. The Pennsylvania-Ohio System material includes photographs of street cars used in various public relations award presentations. In addition to street car material anyone interested in electrical engineering or the history of technology can find the technical drawings, reports and photographs of turbines, generators, and power lines helpful. This material covers the 1920s and 1930s. The Ohio Public Service Company (Series II) legal files contain a large amount of records dealing with the legal aspects of the company. The files contain information on law suits, regulatory agency hearings and real estate sale purchases. The bulk of information covers the years 1911-1943 and would be helpful to students interested in law or business administration.