1793 -- Parisian calligrapher
Valentin Hauy designed a simplified
italic alphabet in
embossed print for use by blind people at his the institution he had founded in 1785.
"We ordered typographical characters to be
cast of the form in which their impression strikes our eyes, and by applying to
these a paper wet, as the printers do, we produced the first exemplar which had
till then appeared of letters whose elevation renders them obvious to the origin
of a library for the use of the blind."
-- An Essay on the Education of the Blind by Hauy
1837 -- Englishman T.M. Lucas used an alphabet of raised phonetic symbols in a transcription of the New Testament. This was system was improved by James H. Frere who invented the return line, in which the one line reads left to right, and the next reads right to left. This allows a page to be read without lifting your finger.
1825 -- 16 year old Louis Braille, a pupil at the Hauy Institute (remember Hauy? He was the first guy I mentioned) invented the current system witch uses completely new graphemes.
Charles Barber had already made a code for the British army to use, made of a small grid of 12 raised dots for each letter, which had the advantage of being able to be both read and written (with an awl) by it's users. Louis cut it down to just 6 dots per letter. The braille system only came into common usage in 1878 after the International Congress in Paris.
1878 -- An american named J.W. Smith modified the traditional British braille so that the most commonly used letters used the least dots. This became known as American braille.