Subseries contains advertising, stock certificates, instructional materials, and internal business materials created by telegraph companies and related entities in the United States and Europe other than Western Union and Postal Telegraph. Companies represented include the American Union Telegraph Company; Boston and Cape Cod Marine Telegraph Co.; Gold and Stock Telegraph Co.; Montreal and New York Printing Telegraph; New Orleans and Ohio Telegraph; New-York and Boston Magnetic Telegraph Association; American District Telegraph Company; Central and South American Telegraph Co.; United States Telegraph Lines; Mackay Radio and Telegraph Company, Inc.; New England Telephone and Telegraph Co.; Commercial Cable Company; National Telegraph Company; New York, Albany, and Buffalo Telegraph Company; American Atlantic Telegraph Company; Cincinnati and Eastern Telegraph Company; American Telegraph Company; Compagnie Française du Télégraphe de Paris a New-York (Paris to New York Telegraph); and the Northern Telegraph Company. Also present are materials related to telephone exchanges, and a certificate for completion of a telegraphy course offered by the Cooper Union in New York City.