No standard Sign language was developed in the US before the 19th century. The deaf population of the country would come up with their versions of Sign language to eliminate the communication barrier. These versions were highly localized; they could even vary from one home to another. Sometimes, local communities intervened and created Sign language to enable communication between deaf and hearing members. For example, during the early 1700s, people from Martha’s Vineyard area in Massachusetts developed and learned Sign language to communicate with the deaf community living in that locality. These local Sign languages together are considered Old American Sign Language.

In 1755, Charles Michel de l'Épé, a French priest, opened the first free school for deaf children in Paris. He standardized the alphabets for French Sign Language and developed the first French Sign Language dictionary. In this dictionary, he compiled the Sign languages created by his students in their homes. 
In 1814, Dr. Thomas Hopkins Gallaudet, the pioneer of American Sign language, traveled to Europe to gather knowledge on deaf education. Gallaudet was a minister from Hartford, Connecticut. In Europe, he met Abbe Sicard, a successor of l'Épé, who was teaching at the National Institute for Deaf-Mutes, Paris. Gallaudet learned teaching methods from Sicard and other teachers like Jean Massieu and Laurent Clerc.

Gallaudet was accompanied by Clerc when he returned to the United States in 1817 to build an institute for deaf education in Connecticut. The school now known as the American School for the Deaf was the first public deaf school that offered free education. Students from all across the US joined the school, and they brought signs from their homes. American Sign language was thus developed based on the French sign system mixed with the local signs that the students brought. In the next 50 years, there were 22 deaf schools across the country, and most of them were founded by the students of Gallaudet and Clerc. These schools continued to follow the method introduced by Clerc’s school, and the method was widely accepted as the standard for American Sign language.

In 1864, Gallaudet’s youngest son Edward Miner Gallaudet founded the first university for the deaf, the National Deaf-Mute College, later renamed as Gallaudet University. Despite the spread of deaf education, misconception about Sign language and its practices were still widespread among the hearing community for another century. In 1960, William Stokoe, a professor at Gallaudet University, published a paper establishing that American Sign Language is a unique language and not a derivative of English. He showed the language has its own syntax and grammar rules, and those are in no way related to English. During this time, Stokoe also published the first American Sign Language dictionary, along with Carl Cronenberg and Dorothy Casterline.