Bradbury Thompson (1911–1995) was an American graphic designer and art director of the twentieth century.
Thompson developed a font called Alphabet 26 or a "monoalphabet" - an alphabet where the uppercase and lowercase forms of each letter were identical, and case was expressed through the letter size only. (In the conventional Latin alphabet, this is already the case for letters like "o" and "O" or "s" and "S", but not for a/A, r/R, etc.)
More information on the Wikipedia page on Bradbury Thomas .
There are various websites on the system eg .