title_body: What was the first book to be published electronically? If we consider an electronic book to be an non-printed book that is only "readable" via an electronic device.  Which book is the first book to be published electronically?
  
  According to Wikipedia "The NLS was established by an act of Congress in 1931 amended in 1934 to include sound recordings, talking books.". It seems reasonable to assume that the first ebook was published in the early 1900's, so what was it?
upvoted_answer: Even though you tried to specify it, the answer still depends a lot on your definition of "book" and "electronic device". Wikipedia has a whole section on History of Ebooks. The quoted term "talking books" most likely refers to something we would call "Audiobooks" today, which even preceded the invention of electronics. Wikipedia on Gramophone Records
  
  On electronics: The thermionic triode was invented in 1906, the transistor was invented in 1925, and the first programmable computer (Zuse's Z3) was built in 1941. Anything that we would consider a "book" needs significant storage space - a single page of text is about 10000 bits of data. Early electronics were not capable of anything of that sort. So the "early 1900s" is not a reasonable assumption.
  
  You also mention "to be published"... that is a different matter entirely. Project Gutenberg started in the 1971, commercial publishers followed later.