While a simile states that one thing is like another, a metaphor asserts that one thing is the other, or is a substitute for the other thing. A metaphor asserts a correlation or resemblance between two things that are otherwise unrelated.
ASL emerged as a language in the American School for the Deaf (ASD), founded in 1817. This school brought together Old French Sign Language, various village sign languages, and home sign systems; ASL was created in this situation of language contact. ASL was influenced by its forerunners but distinct from all of them.
The history of the development of sign language from the very beginning as we know it, its rise in status to an official language in France, its migration to the U.S., and its role worldwide all help build an appreciation for this expressive language and for its legacy of founders who endured persecution on its behalf as well as that of its users.