, ▁founded ▁in ▁ 1 8 7 7 ▁by ▁the ▁family ▁of ▁Alexander ▁Graham ▁Bell ▁ ▁Illinois ▁Bell , ▁the ▁name ▁of ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁Illinois ▁ ▁Indiana ▁Bell , ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁Indiana ▁ ▁Michigan ▁Bell , ▁the ▁subs idi ary ▁of ▁AT & T ▁serving ▁the ▁state ▁of ▁Michigan ▁ ▁Mountain ▁Bell , ▁the ▁name ▁of ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁the ▁US ▁Rock y ▁Mountain ▁region ▁ ▁Nev ada ▁Bell , ▁the ▁Bell ▁System ' s ▁tele phone ▁provider ▁in ▁Nev ada ▁ ▁New ▁Jersey ▁Bell , ▁( 1 9 0 4 – 1 9 8 3 ) ▁ ▁North western ▁Bell , ▁the ▁name ▁of ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁the ▁North ▁Central ▁and ▁North western ▁US ▁ ▁Ohio ▁Bell , ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁most ▁of ▁Ohio ▁ ▁Pacific ▁Bell , ▁the ▁name ▁of ▁the ▁Bell ▁System ' s ▁tele phone ▁operations ▁in ▁California ▁ ▁Regional ▁Bell ▁Oper ating ▁Company , ▁any ▁of ▁the ▁phone ▁companies ▁sp un ▁off ▁from ▁AT & T ▁in ▁ 1 9 8 4 ▁ ▁South ▁Central ▁Bell , ▁the ▁name ▁of ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁the ▁South - Cent ral ▁US ▁ ▁Southern ▁Bell , ▁the ▁name ▁of ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁the ▁S out he astern ▁US ▁ ▁South western ▁Bell , ▁the ▁name ▁of ▁the ▁Bell ▁Oper ating ▁Company ▁serving ▁Kansas , ▁Missouri , ▁Oklahoma , ▁and ▁Texas ▁ ▁Wisconsin ▁Bell , ▁( 1 9 8