Antonio Meucci is credited in some quarters with priority over Alexander Graham Bell in the invention of the telephone.
He was born and educated in Florence; he studied chemical and mechanical engineering at the Florence Academy of Fine Arts and later worked at the Teatro della Pergola in Florence as a stage technician. In 1834 he devised a form of acoustic telephone to communicate between the stage and control room at the Teatro, modelled on ships' speaking pipes. He was alleged at this time to be involved in a conspiracy to bring about Italian unification and was imprisoned for three months in 1834; on release, he and his wife left Italy in 1835.
He went first to Cuba, where his work on Mesmer's theories of natural electricity led him to invent electrotherapy equipment; he also devised a form of telephone through which inarticulate speech could be detected.
His friendship with Garibaldi made him suspect in Cuba and the success of Samuel Morse in inventing the telegraph suggested new opportunities, so in 1850 he relocated to the United States. He set up a tallow candle factory in Staten Island, New York, and used this to finance work on an electromagnetic telephone, constructing various prototypes; however, his finances grew worse and worse and although he filed a patent caveat for one such machine, dubbed the "telettrofono", in 1871, he was unable to convert it to a full patent and unable to renew it in 1874.
When Alexander Graham Bell patented his telephone in 1876, Meucci sued him for infringement of intellectual copyright; a series of lawsuits went all the way to the Supreme Court, and dragged on for the remainder of Meucci's life and beyond: the surviving cases were finally dropped, without decision, in 1897.
There is considerable debate and partisanship on both sides; the issues causing debate can be summarised as whether Meucci's own patent documents mention a mechanism for converting sound waves into electromagnetic ones and back again, the intelligibility of the sounds transmitted by Meucci's device, whether or not Meucci described his invention in the New York Italian newspaper L'Eco d'Italia in 1861, all issues of the paper from that period having perished, and the precise dating of some of Meucci's papers (at one of the court hearings he was accused of having fabricated papers retrospectively).
Meucci died in 1889 with these issues unresolved but having failed to profit from his inventions.