DIAMOND STATE TELEPHONE

'Verizon Delaware, Inc.', formerly 'The Diamond State Telephone Company', is the Bell Operating Company of Delaware, and small parts of southeastern Pennsylvania. Founded in 1897, it became a part of the Bell System in 1905. When the AT&T breakup occurred in 1984, 'DST' became managed by the RBOC Bell Atlantic. In 1994, Bell Atlantic chose to "unify" its brand by legally renaming all of its telephone companies — including 'Diamond State Telephone' to 'Bell Atlantic – Delaware, Inc'.
After the 2000 merger with GTE, Bell Atlantic – Delaware, Inc. became known as Verizon Delaware, Inc.