History of the Telephone - Public Telephone Service
Switchboards, Exchanges, and Rotary Dialing
Service Lines and Switchboards
In 1877, construction of the
first regular telephone line from Boston to Somerville, Massachusetts
was completed. By the end of 1880, there were 47,900 telephones in the
United States. The following year telephone service between Boston and
Providence had been established. Service between New York and Chicago
started in 1892, and between New York and Boston in 1894.
Transcontinental service by overhead wire was not inaugurated until
1915. The first switchboard was set up in Boston in 1877. On January 17,
1882, Leroy Firman received the first patent for a telephone
The first Bell telephone company started in 1878. This is now known as
the American Telephone and Telegraph Company (AT&T), which was
incorporated in 1885. Erna Schneider Hoover began working for Bell Labs in 1945, and in 1971 she patented the first computerized telephone exchange.
Exchanges and Rotary Dialing
The first regular telephone exchange was established in New Haven in
1878. Early telephones were leased in pairs to subscribers. The
subscriber was required to put up his own line to connect with another.
In 1889, Almon B. Strowger a Kansas City undertaker, invented a switch
that could connect one line to any of 100 lines by using relays and
sliders. This switch became known as "The Strowger Switch" and was still
in use in some telephone offices well over 100 years later. Almon
Strowger was issued a patent on March 11, 1891 for the first automatic
The first exchange using the Strowger switch was opened in La Porte,
Indiana in 1892 and initially subscribers had a button on their
telephone to produce the required number of pulses by tapping. An
associate of Strowgers' invented the rotary dial in 1896 which replaced
the button. In 1943, Philadelphia was the last major area to give up
dual service (rotary and button).
In 1889, the first coin-operated telephone or pay
phone was patented William Gray of by Hartford, Connecticut. Gray's pay
phone was first installed and used in the Hartford Bank.