[Sign language] is, in the hands of its masters, a most beautiful and expressive language, for which, in their intercourse with each other and as a means of easily and quickly reaching the minds of the deaf, neither nature nor art has given them a satisfactory substitute.
It is impossible for those who do not understand it to comprehend its possibilities with the deaf, its powerful influence on the moral and social happiness of those deprived of hearing, and its wonderful power of carrying thought to intellects which would otherwise be in perpetual darkness. Nor can they appreciate the hold it has upon the deaf. So long as there are two deaf people upon the face of the earth and they get together, so long will signs be in use.
--J. Schuyler Long
Head teacher, Iowa School for the Deaf
The Sign Language (1910)