Signed Languages exist around the world and facilitate communication for persons who are deaf or hard-of-hearing.
The Milan Conference (sometimes referred to as the Second International Congress on Education of the Deaf) concluded with the belief that pushing deaf persons to learn to lip-read and to speak (oralism) was neither productive for them or for their teachers. While oralism persisted, and does so to this day, most schools teach manual sign-language, and are found throughout every polity in the world.
The NAL-SLC has a special hybrid sign-language, however. Mssrs Gallaudet and LeClerc brought Old Francien Sign Language to America, founding the Hartford School for the Deaf and Dumb, giving rise to what is now known as League Sign Language (LSL). Not all of the NAL uses the same sign language. Mueva Sefarad for example, is believed to have developed their own sign language prior to admission into the NAL.
The remnants of Florida-Caribbea have a somewhat more complex situation. The first schools for the deaf in Florida were founded by teachers from the NAL, and thus, Floridian Sign Language (FlSL) was originally based on League Sign Language. Cuba (and perhaps Porto Rico and Hispaniola) developed their own sign languages. Initially, FlSL was the prestige sign language of FC, but later, Cuban Sign Language (CSL) came to the fore, in part due to hostility towards the NAL.
Louisianne (LSLo) and New Francy both use dialects of LSL. Data on the rest of North America in this regard is spotty. LSLo has the unique distinction of having embraced the manual sign languages of the cultures surrounding it, and many of the common Plains Indian Sign Language signs still survive in northern Louisianne especially, but throughout the nation, and having had a profound influence on Lousiaianne Sign Language. With the loss of Les Plaines during the 1828 War, a schism has developped, and there is some lingustic differences between LSLo and Lousianne-Les Plaines Signed Language.
The Federated Kingdoms each developed their own sign language, the English variety often called British Sign Language. Australasia's subdivisions followed suit with their home crown.
Because of the greater status of manualism, the deaf community is one of the more highly connected minorities. Televised interpreters have been in play since the advent of television, almost, and the written format for sign language has developed in two forms, Sign Writing1 or Stokoe Notation2. While others exist, these two are the most commonly used. This has led to a greater standardization in sign languages.