Bell System / A. T. & T National Network

Bell Labs and A. T. & T. experimented with interconnection of TV stations in the mid 40s, with the New York to Boston route. In 1946 they started expanding the network, using both coaxial cable and microwave links. By 1949 the network covered most of the east coast and midwest. By 1951 some of the south was incorporated, and work was underway to link the west coast. By 1957 the entire country was linked. This network provided interconnection of TV stations until satellite networks were developed in the 70s and 80s.

From RCA 1945 booklet

DuMont network affiliates, 1949

1950 Network Map

Courtesy of Bob Dobush

1958 Network Map