AT&T Inc (NYSE: T) - one of the largest American telecommunications companies. Is the largest supplier as a local, and long distance telephony in the USA, as well as the second largest wireless service provider in the United States (77 million users). Total number of AT clients&T more 150 million people. Headquarters - Dallas, Texas. History American Telephone and Telegraph Company (AT&T Corp.) was established in 1885 year. For a long time it was a monopolist in the US long-distance and local communications market. In 1983-1984, under pressure from the US Department of Justice, within the framework of the antitrust process, it spun off the local telephony business and focused on long-distance services. One of the highlighted in 1983 the company received the name Southwestern Bell Corporation. IN 1995 year this company changed its name to SBC. IN 2005 SBC, becoming by this time the largest telecommunications holding in the United States, acquired for $16 billion AT itself&T, from which once stood out. Moreover, the name AT&T passed to the merged company.