First, AT&T and the regional Bell Operating Companies (RBOCs) were split up in 1984. Who knew then that there was a twenty-five year plan put into effect to put it all back together again?
Then, just a few years ago, AT&T Wireless was sold off to SBC, which merged it with Cingular, which was a jointly owned company (SBC and BellSouth). Then SBC bought what was left of AT&T and the SBC name was dropped in favor of AT&T. Then the new AT&T bought BellSouth. Now the Cingular name will be dropped and the cellphone service will be re-branded "AT&T."