AT&T The AT+T Corporation, formerly known as The American Telephone and Telegraph Company, was incorporated on March 3, 1885 in New York as a wholly owned subsidiary of The American Bell Telephone Company. Its original purpose was to manage and expand the burgeoning toll (long distance) business of American Bell and its licensees. It continued as the long distance company until December 30, 1899 when it assumed the business and property of American Bell and became the parent company of the Bell System. For most of its history, the company functioned as a legally sanctioned, regulated monopoly. No compe