Southwestern Bell Telephone Company

"Southwestern Bell Telephone traces its roots to The Missouri and Kansas Telephone Company, which was founded in 1882. It was consolidated under a single management unit of the Bell System with Southwestern Telegraph and Telephone Company of Texas-Arkansas, Pioneer Telephone and Telegraph Company of Oklahoma, and The Bell Telephone Company of Missouri—also called The Missouri Bell Telephone Company—on March 1, 1912. These companies comprised the "Southwestern System" of the Bell System. The latter three companies were legally merged into Missouri and Kansas Telephone Company in 1917, which was renamed Southwestern Bell Telephone Company" .--Wikipedia