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The American Bell Telephone Company formed the American Telephone and Telegraph Company (AT&T) subsidiary in 1885. The latter was a successor of the original Bell Telephone Company founded by Alexander Graham Bell in 1877. After expanding services to Arkansas, Kansas, Oklahoma and Texas, through a series of mergers, it became Southwestern Bell Telephone Company in 1920, which was then a subsidiary of American Telephone and Telegraph Company. The company began its history as the American District Telegraph Company, formed in St. ĭuring most of the 20th century, AT&T had a monopoly on phone service in the United States. As of 2022, AT&T was ranked 13th on the Fortune 500 rankings of the largest United States corporations, with revenues of $168.8 billion. It is the world's largest telecommunications company by revenue and the third largest provider of mobile telephone services in the U.S.
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is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas.
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