AT & T is the world’s largest provider of mobile telephone and telecommunication services. The company’s headquarters is situated in Whitacre Tower, Downtown Dallas, Texas. AT & T was established in 1885 as the Southwestern Bell Corporation by Alexander Graham Bell, Gardiner Green Hubbard, and Thomas Sanders, shortly after Alexander Graham Bell, the inventor of the telephone, applied for and got a patent. AT & T was a subsidiary company of the Southwestern Bell Corporation, established in 1885, and acquired in 1899.

AT & T established a network of subsidiaries throughout the United States and Canada, monopolizing the phone network industry in the 20th Century. Much of this monopoly was thanks to the Kingsbury Commitment, which settled the government’s antitrust challenge against the organization out of the bounds of the courts. The group of companies under the Bell name which dominated the telephone industry was known as the Bell System. The organization was also the world’s single largest telephone company for some time.

The corporation broke up in the 1980s and was asked to divest all its regional subsidiaries. The breakup also created the Southwestern Bell Corporation around the same time. Since then, the company has acquired other key players in the market, including Metromedia in 1987 followed by several cable companies in the 1980s, as well as a host of telecommunications companies in the 1990s. In recent times, too, the company has made several notable acquisitions, including the Mexican carrier Lusacell in 2014, and the Mexican wireless business, NI Holdings. AT & T later merged the two companies it acquired and formed AT & T Mexico.