Which sign language developed largely from French Sign Language?

American Sign Language developed largely from French Sign Language, with additional influence from local signing traditions.

Laurent Clerc, a Deaf educator from France, traveled to the United States in 1816 with Thomas Hopkins Gallaudet. In 1817 they helped establish the American School for the Deaf in Hartford, Connecticut. Teaching at the school helped French Sign Language interact with signs already used in the United States.

American Sign Language, commonly called ASL, became a natural language with its own grammar, vocabulary, and regional variation. It is not simply signed English, and its sentence structure can differ substantially from spoken or written English.

Sign languages are not universal. British Sign Language, for example, belongs to a different sign-language family from ASL despite both being used in countries where English is widely spoken. ASL is used primarily in the United States and parts of Canada.