Key points in AT&T’s history:

1984
The government orders a break-up of AT&T. The long distance company keeps the AT&T name and seven regional “Baby Bells” are formed to offer local telephone service.

1991
In an ill-advised move at diversification, AT&T acquires computer maker NCR for $7.5 billion in an effort to expand beyond telephone services. Five years later AT&T sells NCR.

1996
AT&T sells the former Bell Labs unit, which is renamed Lucent. Lucent raises $3 billion in an initial public offering and quickly becomes a Wall Street darling.

1997
Michael Armstrong, the former CEO of Hughes Electronics, replaces Robert Allen as CEO, marking the first time AT&T goes outside its management ranks for a CEO.

1998
AT&T gobbles up local carrier Teleport Communications as part of a new strategy to reenter the local telephone market.

1999
AT&T buys cable giant TCI in a blockbuster $48 billion deal, giving the company access to 33 million homes. The deal also includes Liberty Media and an interest, later expanded, in cable Internet company At Home which later becomes Excite@Home.

2000
AT&T’s foray into cable continues with the $44 billion acquisition of MediaOne.

With its share price tumbling, Armstrong announces plans to break up AT&T into four separate companies focusing on consumer long distance, business services, broadband services and wireless services.

Source: Company reports, Hoovers.