Milestones:

1831 Michael Faraday proved that vibrations of metal could be converted to electrical impulses
1861 Johann Philip Reis built a apparatus that changed sound to electricity and back again to sound
1871 Antonio Meucci filed his patent caveat (notice of intention to take out a patent)
1874 A. G. Bell while working on a multiple telegraph, developed the basic ideas for the telephon
1875 Bell files first patent for improved telegraphy
1876 Bell and Watson transmit the first complete sentence
1876 Bell files patent application on February 14,. patent issues March 7
1876 Elisha Gray filed his patent caveat (notice of intention to take out a patent) on February 14
1877 Formed Bell Telephone Company to operate local telephone exchange operation
1877 first city exchange installed in Hartford, Connecticut
1879 First exchange outside the United States was built in London, England
1880 invented the photophone, which transmits speech by light rays
1882 acquired a controlling interest in the Western Electric Company, Elisha Gray's company
1883 First exchange linking two major cities was established between New York and Boston
1885 formed American Telephone and Telegraph Company to operate the long distance network.
1888 coin operated pay telephone was patented by William Gray of Hartford, Connecticut
1891 first automatic telephone exchange was patented by Almon Strowger of Kansas City
1921 The Detroit Police Department, began experimentation with one-way vehicular mobile service.
1928 Detroit Police commenced regular one-way radio communication with all its patrol cars.
1933 Bayonne, NJ Police Department initiated regular two-way communications with its patrol cars
1936 Alton Dickieson, H.I. Romnes and D. Mitchell begin design of AT&T's mobile phone system
1940 Connecticut State Police began statewide two-way, on the frequency modulated (FM)
1941 FM mobile radio became standard throughout the country following the success in Connecticut
1946 A driver in St. Louis, Mo., placed a phone call,it was the first AT&T mobile telephone call.
1948 wireless telephone service was available in almost 100 cities and highway corridors.
1947 cellular telephone service conceived by D.H. Ring at Bell Labs, but the technology didn't exist
1962 The first commercial touch-tone phones were a big hit in their preview at Seattle World's Fair.
1970 commercial Picture phone service debuted in downtown Pittsburgh, Pennsylvania.
1971 Richard Frenkiel and Joel Engel of AT&T applied computers and electronics to make it work.
1973 Martin Cooper of Motorola made the first cellphone call to his rival Joe Engel of AT&T Bell Labs
1978 AT&T conducted FCC-authorized field trials in Chicago and Newark, N.J.
1979 the first cellular network was launched in Japan.
1982 FCC granted commercial licenses to an AT&T subsidiary, Advanced Mobile Phone Service
1983 AMPS was then divided among the local companies as part of the planning for divestiture
1983 Illinois Bell opened the first commercial cellular system in October
 
The story
Probably no means of communication has revolutionized the daily lives of ordinary people more than the telephone. Simply described, it is a system which converts sound, specifically the human voice, to electrical impulses of various frequencies and then back to a tone that sounds like the original voice. In 1831, Englishman Michael Faraday (1791-1867) proved that vibrations of metal could be converted to electrical impulses. This was the technological basis of the telephone, but no one actually used this system to transmit sound until 1861. In that year, Johann Philip Reis (1834-1874) in Germany is said to have built a simple apparatus that changed sound to electricity and back again to sound. A crude device, it was incapable of transmitting most frequencies, and it was never fully developed.