Not a lot is known about Sign Language until the 18th century. It is known that quite a few Deaf people lived in Martha's Vineyard, which is an island off the coast of Cape Cod. Hearing people and Deaf people there used Sign Language to communicate. It was estimated at that time that there were 2,000 Deaf people in the United States.
Until the 18th century, Deaf individuals were not allowed to conduct trade, buy homes, receive education, or even sign contracts of marriage. They were basically denied fundamental human rights.
In the 1550's Pedro Ponce de León developed a private system of gestures to aid student-teacher interaction, essentially this was the first conventionalized sign system. Geronimo Cardano, who proclaimed that the deaf hear by reading and speak by writing, inspired De León.
Now this sign system de León created was only a prelude to his main objective, which was the teaching of speech. At this time Canon Law proclaimed that those who could speak were regarded persons at law. These certain Deaf individuals were able to inherit, enter into contracts, and assume legal obligations. It is Ponce de León who is known as the first successful teacher of the Deaf people on record.
Another man who is claimed to have been the first person to teach Deaf people to speak is Juan Pablo Martin Bonet. He claimed himself as the inventor of a system whereby speech sound could be represented by one visible [hand] shape that never varied and permitted the Deaf individuals to associate between an utters sound and its fingerspelling counter-part. Today people think Bonet is the inventor of Sign Language and of the manual alphabet, but it was never his nor did he use it to teach, it came from Ponce de León.
Now it was Jacob Pereire who was responsible for the spread of Ponce de León's manual alphabet throughout Europe. He had employed the manual alphabet in an effort to teach his Deaf sister to speak, which led to his life long career of teaching Deaf families to communicate. He adapted the single - handed alphabet by adding his own set of handshapes, each corresponding to one sound. There were 30 plus shapes for numbers and punctuation's. He stated that each handshape designates simultaneously the position and movement of speech organs suitable to produce the sound, and the letters that normal writing requires to represent this very sound.
