History of the AT&T Network

Historical Film Gallery

Explore the history of the AT&T network with these vintage film clips from the AT&T Archives.

See how the development of the high-vacuum-tube amplifier in 1913 made telephone communications across great distances possible.
See the construction of the first transcontinental telephone in 1914.
Trace the expansion of the telephone network from 1915 to 1935.
Learn about coaxial cable, the first broadband transmission medium, invented by AT&T in 1929.
See how AT&T installed the long distance network'sfirst coaxial cable, between Minneapolis and Stevens Point, Wis., in 1941.
Learn how the first broadband coaxial cable transmitted hundreds of calls on one pair of copper tubes.
See the first microwave radio-relay system in the long distance network. Microwave radio relay and coaxial cable together formed the backbone of the AT&T long distance network from the 1950s until the 1980s.

Networking was the original mission of AT&T, and it has remained at the core of what we do ever since.

"1000 Miles and Back" AT&T Advertising Brochure

The American Telephone and Telegraph Company was incorporated in New York in 1885 as a subsidiary of the American Bell Telephone Company. AT&T’s corporate charter laid out the firm’s mission: “Connect one or more points in each and every city, town or place in the State of New York with one or more points in every other city, town or place in said State and in each and every other of the United States, Canada and Mexico; and each and every of said cities, towns and places is to be connected with each and every other city, town or place in said states and countries, and also by cable and other appropriate means with the rest of the known world.”

Those were lofty goals less than a decade after the telephone’s invention. AT&T would accomplish all that it envisioned, but it would take many years.

The buildout begins

AT&T began building its network out from New York in several directions. The first line, to Philadelphia, opened in 1886. AT&T reached a major milestone in 1892, when it began telephone service between New York and Chicago. This 950–mile circuit was close to the longest line possible with the existing technology. But one innovation, loading coils, extended the limit to around 2,000 miles, and a second, the vacuum tube amplifier (or repeater), made lines of any length feasible. With repeaters in the line, AT&T opened transcontinental telephone service in 1915.

Meanwhile, in 1899, AT&T acquired the assets of its parent, American Bell, and became the parent company of the Bell Telephone System. AT&T’s original operation became known as the Long Lines division.

Not just talk

(Photo of company officials inaugurating telephone service between New York and Paris.)

AT&T President Walter Gifford and other company officials inaugurate telephone service between New York and Paris, March 28, 1928.

The network carried more than just conversations. Private telegraph service had been part of the traffic from the earliest days. In the 1920s, AT&T began transmitting radio programs to stations across the country and wire photos (via an early form of fax) to newspapers. In the 1930s, switched teletypewriter service provided digital transmission of text. In the 1940s, television–networking service sent programs to distant stations. In the late 1950s, AT&T introduced the first commercial modems, so those new devices called computers could communicate with each other.

Going global

Gradually, AT&T fulfilled the global vision of its charter, opening service to Cuba in 1921, Great Britain in 1927, and Japan in 1934. Conversations crossed North America by wire, and the ocean by radio telephony. In 1935, two AT&T executives made the first around-the-world phone call. They spoke from adjoining rooms in New York, but their voices circled the globe.

The network expanded in scale as well as scope. AT&T added additional circuits as traffic grew. By 1940 there were four separate routes between the East and West coasts.

Network components

One way to think of the network over the course of its long history is as having three components:

Transmission, the routes over which the messages traveled
Switching, the systems for routing the messages
Management, the intelligence that makes the whole system function.

Keeping pace with the growing demands for telecommunications required continuous innovation, improvement and expansion in each area. Transmission media evolved from open wires to cable, coaxial cable, microwave relays and to fiber optics. Switching evolved from operators at plug boards to electromechanical automatic switches and special- purpose digital computers. And management evolved from master switching plans and route books to hierarchical networks and dynamic networks with real–time monitoring and control. AT&T’s 21st-century network is the product of this evolution.