Louis Laurent Marie Clerc was a Deaf French teacher. He was taught by Abbé Sicard at the Institution Nationale des Sourds-Muets in Paris. In 1815 he traveled with Sicard and Massieu to England to give a lecture and happened upon Thomas Hopkins Gallaudet who was traveling in search of means for instructing deaf children.

Gallaudet was invited to visit the school in Paris. After a few months with Clerc at the school, Rev. Gallaudet invited Clerc to accompany him to the United States. During the trip across the ocean, Clerc learned English from Gallaudet, and Gallaudet learned sign language from Clerc. After arriving in America, they worked together to establish the first permanent school for the Deaf in Hartford, Connecticut, which is now known as the American School for the Deaf.

Clerc is considered "The Apostle of the Deaf in America" and is regarded as the most renowned deaf person in American Deaf History as he introduced a standardized form of sign language with a syntax and grammar.