I strongly recommend YOU do some research before relying on your recollections. I did and found you were wrong in generalizing based on your own recollections of events a long time ago.
I use several things to clue in on what year it was I did something or encountered a certain device.
(1) I associate my college and higher education year by year, and within a year by where I lived. (2) I associate my ownership or use of various sorts of typewriters with what year I still lived at home, or was in highschool, or in college, and whether or not I was the editor of my dormitory newspaper. (3) I relate each year of my employment with its reference to specific college courses (which I can check on my computer ~ everyone should keep a copy). There were 3 different graduate programs BTW, over a period of years, with marriage mixed in, and employment.
Before posting a specific date for the appearance of a particular type of equipment, e.g. Royal Typewriters, Underwood Typewriters, manual, electric, spacing electric, manual or auto return (yes there were both on manuals), first computer (IBM 360 ~ remember those?), first laptop, first this and that by year associated with counts based on when kids were born, house purchased, car driven, and so forth, I always find a respected technology time-line site to reference in case of dispute.
So, where did I make a mistake? I never put anything on the net that I have not BEFOREHAND validated on the net or in a book.
http://www-03.ibm.com/ibm/history/exhibits/modelb/modelb_history.html ~ great site for typewriter history. 1914 ~ by IBM’s estimation ~ that’s the year the first electric typewriter of value was introduced. BEFORE WWII, and actually BEFORE WWI ~ that’s 1915 ~ August or thereabouts eh.