Martha's Vineyard, an island five miles off the southeastern shore of Massachusetts in the U.S., is notable for its history of the majority of sign language users.
The population on the Martha's Vineyard island in the 18th century had a high rate of deaf heredity. By the mid-1700s, inhabitants, both deaf and hearing islanders, developed an indigenous signed language, called Martha's Vineyard Sign Language (MVSL). The birth rate for deaf children ws 1 in 155 on the island.
Groce, Nora Ellen. Everyone here spoke sign language: Hereditary deafness on Martha's Vineyard. Harvard University Press. 1985.
Kageleiry, J. (1999). "The island that spoke by hand." Yankee 63(3), p48.
"Show me a Sign" (2020) by Ann Clare LeZotte (Deaf author and librarian). It's a #OwnVoices historical fictional novel based on real-life events. It's a great reading for preteens and beyond. Schneider Family Book Award for Middle Grades (2021)
"Set Me Free" (2021) by Ann Clare LeZotte (Deaf author). This book is a "masterful stand-alone companion to Show Me a Sign". Reading age: 8-12.
You may also be interested in Nicaraguan Sign Language: a scientific study of language emergence.