The Bell System held a virtual monopoly over telephony infrastructure in the United States from around the early 20th century until January 8, 1982. It consisted of parent the American Telephone & Telegraph Company (AT&T), which directly provided long-distance service, while local service was provided by 24 local Bell Operating Companies, which owned whole or in part by AT&T, while its manufacturing subsidiary Western Electric produced almost all of its equipment, which was largely designed at the research and development subsidiary Bell Labs. As a result, AT&T had substantial control over the United States' communications infrastructure.
The breakup of the system was initiated in 1974 when the United States Department of Justice filed United States v. AT&T, an antitrust lawsuit against AT&T. Relinquishing ownership of Western Electric was one of the Justice Department’s primary demands.