In the early 2000's there was the "original AT&T", a separate wireless company called AT&T Wireless, then Cingular who was the wireless group/division of SBC (Southwestern Bell) and SBC themselves.
Consolidation started with Cingular buying AT&T Wireless. Then SBC bought AT&T and simply kept the AT&T brand. Eventually the Cingular brand went away and they went back to AT&T and AT&T Wireless.
Wheeeee! The AT&T of today is basically SBC with all the old assets rolled in. SBC bought AT&T, not the other way around.
Consolidation started with Cingular buying AT&T Wireless. Then SBC bought AT&T and simply kept the AT&T brand. Eventually the Cingular brand went away and they went back to AT&T and AT&T Wireless.
Wheeeee! The AT&T of today is basically SBC with all the old assets rolled in. SBC bought AT&T, not the other way around.
Source: worked there through it all