Conectiv, Inc. is a holding company formed in 1998 by the merger of Atlantic Electric Incorporated and Delmarva Power and Light Company, two large regional power utilities that supplied Southern New Jersey and the Delmarva Peninsula. The majority of the images in this collection come from the Delmarva Power and Light Company (DP&L), a predecessor of Conectiv, Inc. The images can generally be divided into three categories: DP&L equipment and facilities, DP&L employees, and views of buildings, both commercial and residential, throughout northern Delaware.

The Edison Electric Institute is the trade association of the electric utility industry. The minutes of the Institute's Transmission and Distributing Committee (1935, 1941-1970) include both business transactions of the committee and professional papers of representatives of member utility companies on a variety of subjects related to the transmission and distribution of electricty.

Leroy Nelson Houck (1895-1980) was an electrician with the Pennsylvania Water & Power Company. He spent a large portion of his career working in the Load Dispatcher's Office. Pennsylvania Water & Power Company was established to store, transport, and generate water power for both commercial and manufacturing purposes. The Holtwood facility outside of Lancaster, Pennsylvania, was the first power plant to have both a hydroelectric generator and a coal power generator. This small collection consists of pamphlets, photographs, and booklets related to the Pennsylvania Water & Power Co. documenting Houck's experiences as an employee there. There are manuals, booklets, and brochures about Holtwood and the Safe Harbor Dam.

Pennsylvania Power & Light traces its origins to the various water and gas light companies that began operating in the eastern part of the state during the mid-nineteenth century. The records of the Pennsylvania Power & Light Company predecessor and subsidiary companies document the history of the gas and electric utility industry in eastern Pennsylvania in the years between 1853 and 1957. The collection includes both the administrative and operating records of more than 1100 companies that merged to form the PP&L system.

The Philadelphia Electric Company was incorporated under the laws of Pennsylvania on October 31, 1929, as a merger of The Philadelphia Electric Company (incorporated in Pa. on October 27, 1902), the Philadelphia Suburban-Counties Gas & Electric Company, and three other small utility companies. It is the primary gas and electric company for Philadelphia, its surrounding counties and Cecil and Harford Counties in northeastern Maryland. Their records consist of microfilm copies of the minute books of about 150 of the predecessor companies of the Philadelphia Electric Company.

Consists of reports, data, and other material produced by Delaware Electric Power Co. for the Securities and Exchange Commission. Included in this series are annual financial reports (10-K forms) from Delaware Electric Power and cost estimates of operating companies separated by the Public Utility Holding Company Act of 1935. Most notable are documents regarding the surrender of stock by the United Gas Improvement Company to Delaware Electric Power by act of legislation, and the eventual separation of the latter company's utilities from its transit operations in 1941-1942. Accordingly, Russel S. Stoughton's purchase of Delaware Coach Co. in 1950-1951 is also represented.