Three of the companies are owned by Verizon Communications:
One company is owned by Frontier Communications:
The Chesapeake and Potomac Telephone Company was founded in June 1883. C&P Telephone Co. provided telephone service to Washington, D.C.
In July 1969, President Richard Nixon's telephone call to astronauts on the moon originated from C&P Telephone Co. equipment.
The C&P Telephone Company of Maryland was founded in 1884 as The Chesapeake and Potomac Telephone Company of Baltimore City. It changed its name to The Chesapeake and Potomac Telephone Company of Maryland on January 3, 1956, and the corporate name at this point changed to C&P Telephone of Maryland.