Who invented sign language?

Cave man sign language

The earliest humans did not use words to communicate. They used sign languages that were absolutely different from the sign language used today. Even animals use sign language to communicate with each other. Similarly, body language was also used to communicate and pass on messages in the early humans. Thus, in some form or the other, communication was carried out by the early humans in form of a distinct sign language. However, it is impossible to point out who invented sign language in the early ages, because it has been carried forward through generations.

The wild wild west and sign language

The sign language arrived on the lands of America with the efforts of two men. 

 Laurent Clerk and Thomas Hopkins Gallaudet opened the first American school for the deaf, after about 45 years of L'Epee's school in Paris. 

                                                 

The children who attended their school came from all over the country and thus they integrated many methods into the school's existing program. This helped in creation of the American Sign Language.
These early influences and contributions lead to the development of the sign language. The sign language has really helped the deaf to communicate with people around them. The credit as the inventor of sign language should be given to the early cavemen who used it even before words were created. Thus, one person cannot be pin-pointed for the invention of sign language. It was the contribution of many people which led to the creation of sign language.