Of Industry Founded March 3, 1885; 132 years ago ( 1885-03-03),, Founder Headquarters,, Products,, Local Service,,,,, Business Solutions (1885–1899) (2005-present) Website AT&T Corp. Iphone Screen Tilt Unlock. Unlock Iphone Without Passcode And Siri here. , originally the American Telephone and Telegraph Company, is the subsidiary of that provides voice, video, data, and telecommunications and professional services to,, and government agencies. Founded in 1885 as the original American Telephone and Telegraph Company, it was at times the world's largest company, the world's largest operator, and a regulated. At its peak in the 1950s and 1960s, it employed one million people and the company revenue was roughly $3 billion annually. In 2005, AT&T was purchased by and former subsidiary SBC Communications for more than $16 billion ($20 billion in present-day terms ). SBC then changed its name to. AT&T Corporate Logo, 1964–1969 AT&T started with Bell Patent Association, a legal entity established in 1874 to protect the patent rights of after he invented the telephone system.