April is National Deaf History Month, an annual celebration of the advancements of Americans who are deaf or hard of hearing. The event was introduced in 1997 by the National Association of the Deaf. This civil rights organization has provided impassioned advocacy by and for people with hearing loss since 1880. The story of deafness in North America, however, began long before then, with a time line that reaches back to antiquity.The oldest remnant of Deaf history on the continent is Hand Talk, or Plains Indian Sign Language. This Native American mode of communication predates the arrival of European colonizers by centuries. Hand Talk developed as a visual, common language among hundreds of diverse Indigenous nations and tribes across North America that spoke different languages. Although Hand Talk was devised for and by hearing people, it provided people with hearing loss a way to engage with one another and with the hearing world. Only a few Native Americans use Hand Talk today.Deaf communities are a rarity in early American history. One, however, took root on the island of Martha's Vineyard, Massachusetts, in the late 17th century. The high incidence of deafness in the region was due to a hereditary genetic difference among the English settlers who immigrated there. With a significant portion of the population born deaf, Martha's Vineyard Sign Language emerged. It provided a means of communication that was learned by almost everyone in the community, including hearing residents. The language was handed down from generation to generation for centuries until the last person to use it died in 1952.A pivotal event in American Deaf history was the establishment of the American School for the Deaf in Hartford, Connecticut, in 1817. The first institution of its kind, the school was founded by theologian Thomas Gallaudet and French educator Laurent Clerc. Their paths first crossed in Europe, where Gallaudet had been investigating deaf educational techniques. Impressed with the French method of manual communication, Gallaudet returned to the United States with Clerc to open a school that would teach the method.It didn't take long for children from across the country to enroll. They brought with them the signs they used at home to communicate with their families. These signs melded with signs from French Sign Language to form American Sign Language (ASL). It is now the primary mode of Deaf communication in the United States. Gallaudet and Clerc went on to impart their educational method and ASL to Deaf communities across the country, and by 1863, 22 schools had been established nationwide. In 1864, Gallaudet's son established the nation's first Deaf college in Washington, D.C., which now bears his family name.Some significant dates in American Deaf history involve the passing of landmark legislation that protects the civil rights of people with hearing loss. These achievements were in large part due to the unstinting efforts of the National Association of the Deaf. The Education for All Handicapped Children Act of 1975 (now called the Individuals with Disabilities Education Act) requires public schools to provide free education that meets the needs of children with hearing loss and other disabilities. And the Americans with Disabilities Act of 1990 outlaws discrimination against people with disabilities in employment, transportation, public accommodations, communications, and access to government services.These are just a few milestones in American Deaf history. Its time line brims with a multitude of activists who were deaf and demanded to be heard, and Deaf History Month salutes them all.