Also, referencing the notes on American Sign language, I'll admit I had not thought of it as a language, despite the name. Nor had I considered the fact that it would have dialects.
Thought some here might find it interesting.
http://www.ethnologue.com/show_country.asp?name=US
Dialects: Black American Sign Language, Tactile Sign Language. In Canada there are dialect differences with USA ASL and regional differences from east to west. Structurally and grammatically distinct from Quebec Sign Language (LSQ). Has grammatical characteristics independent of English. A few adults know both ASL and LSQ. Most signers from eastern Canada use ASL with some British Sign Language vocabulary, a remnant from Maritime Sign Language, which came from British Sign Language. Black American Sign Language developed in segregated schools in the south. It contains much sign vocabulary not in ASL and some different grammatical structure. Tactile Sign Language is used by over 900 persons in Louisiana who know ASL, but have lost their sight from a generic cause: Usher's Syndrome. They communicate by touch on each other's wrists. Some have migrated to Seattle. Some have learned Braille. ASL has 43% lexical similarity with French Sign Language in an 872-word list. Classification: Deaf sign language