On January 8th, 1982, the United States ruled that the Bell System must be broken up as they held a virtual monopoly over telephony infrastructure. The United States Department of Justice initiated an antitrust lawsuit against AT&T in 1974 under The United States v. AT&T. At that time, AT&T held substantial control over the U.S. communications infrastructure, and was the sole telephone provider throughout the country. Once AT&T believed they would lose the suit, they proposed a breakup. Effective January 1st, 1984, ownership of the Bell System's many local operating companies were transferred to seven independent Regional Bell Operating Companies, which reduced the book value of AT&T by approximately 70%.
