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.

Delmarva Power and Light Company is a regulated energy company that provides electricity and natural gas services to customers in the Delmarva Peninsula. These 1926 images document the construction of gas towers and substations at the Christiana and Brandywine power plants in the Wilmington, Delaware.

Garrett, Miller & Co. was a Wilmington, Delaware-based electrical company that served the public in the nineteenth and twentieth centuries. Frank S. Garrett (1869-1950), grandson of abolitionist Thomas Garrett (1789-1871), and Henry K. Miller (1861-1925) purchased the electrical department of Delaware Electric & Supply, to form their own company, Garrett, Miller, and Company. The company sold electrical supplies for construction and, into the 1900s, began selling smaller electrical appliances, including toasters, lamps, and vacuum cleaners. This collection includes eleven letters between Garrett, Miller & Co., and other Delaware area businesses and institutions. These include Alfred A. Curtis and Lewis C. Vandegrift, of Bradford, Vandegrift & Byrne, and the Town Council of Newark, Delaware. The items are dated between May 1896 through February 1897.

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.

Levi C. Stang (1890-1962) was an electrical engineer and general manager of several electric companies throughout the Midwest. His scrapbook chronicles his career and employment as an electrical engineer through selected letters and correspondence, newspaper and other clippings, blueprints, and photographs.

The Pennsylvania Power & Light Co. is an energy utility and transmission distributer based in Allentown, Pennsylvania. Arising from a business merger, the company was founded on June 4, 1920, and soon after began providing energy to eastern and central Pennsylvania. Renamed PP&L Corporation circa 1995, the company continues to operate as an energy provider within northeastern Pennsylvania. The collection consists primarily of photographs that depict sites of various PP&L subsidiaries and those directly operated by the company. It is a resource that can be used for insight into PP&L's early operations and eastern and central Pennsylvania industrial development. Images within this collection range from 1920 to 1973. Researchers interested in electric power transmission and its development within the state of Pennsylvania would find this collection useful.

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 Stanton steam-generated power plant began operation at Harding, Pennsylvania in 1927. It was run by the Scranton Electric Company, which was later acquired by the Pennsylvania Power & Light Company. Most of the photographs in this collection are snapshots showing the plant and employees between 1934 and 1936. There are many that show a flood which took place on March 17, 1936. The three newspaper clippings report on the demolition of the plant between 1973 and 1976.

Thomas Parke Hughes (1923-2014), was one of the leading historians of technology of his era. This collection consists of files relating to the research and production of Professor Hughes' two prize-winning books, Networks of Power, and Elmer Sperry: Inventor and Engineer. Also included are Elmer Sperry's original desk diaries.