Katie West, the last deaf person born into the island's sign-language tradition, died in 1952,[5] though there were a few elderly residents still able to recall MVSL when researchers started examining the language in the 1980s.
The ancestry of most of the deaf population of Martha's Vineyard can be traced to a forested area in the south of England known as the Weald—specifically the part of the Weald in the county of Kent.
Families from a Puritan community in the Kentish Weald emigrated to the Massachusetts Bay Colony in British America in the early 17th century, and many of their descendants later settled on Martha's Vineyard.
By 1710, the migration had virtually ceased, and the endogamous community that was created contained a high incidence of hereditary deafness that persisted for over 200 years.
From the late 18th to the early 20th century, virtually everybody on Martha's Vineyard possessed some degree of fluency in the language.
At the outset of the 20th century, the previously isolated community of fishers and farmers began to see an influx of tourists that would become a mainstay in the island's economy.
Deaf people would work both complex and simple jobs, attend island events, and participate within the community.
The sign language was spoken and taught to hearing children as early as their first years to help them communicate with the many deaf people they would encounter in school.
[11] Non-manual markers, such as lip movement and facial expressions as well as hand gestures and mannerisms were all studied.
Additionally, as transportation became easier in the 19th century, the influx of hearing people meant that more genetic diversity was introduced, and hereditary deafness was no longer commonplace.
Following her death, Oliver Sacks noted in the 1980s that some elderly hearing residents of the island could remember a few signs, but the language truly died out after this point.
[14] Show Me a Sign by Ann Clare LeZotte is a middle grade novel about the thriving deaf community living on Martha's Vineyard in the early part of the 19th century.