Back in the mid 19th century, when Samuel Morse was inventing the Morse code, he wanted to give the simplest codes to the most frequently used letters. He realized he had to find out out the frequency of letter use, so guess what he did - he consulted letterpress printers! He visited a printshop to count the number of letters in a set of printers' type, because printers had quantities of letter type based exactly on how frequently they needed to use them to set up a page for printing. How about that as a good example of not having to reinvent the wheel, so to speak?!
This was the frequency of English alphabet letter use, according to Morse. (Thanks, Oxford Dictionary website.) So, the least used letters are actually J, X, and Z while the most used letter of the English alphabet, by far, is E. (This chart might come in handy for Wheel of Fortune contestants.) I wonder how the frequency might change if we distinguished between upper and lower case letters, too? And has it all changed over time? English is, after all, a living language. Ahhh... so much to learn, so little time.
So, anyway, I was in error when I wrote in my last post that J and U were placed in the end cubbies of the California Job Case because they were the least used letters. Since I've now finished the assigned reading for my class, I'm oh so much better informed! (Note to my screenprinting students: It DOES help to read the assignments.) The alphabet used by early printers did not include J's and U's. When J and U were added later, printers would have had to spend a lot of time shifting all the letters into different cubbies in the multitude of font cases in the printshop to maintain correct letter sequencing. Printers apparently said, "To hell with THAT!" and put the J and U type pieces in the end cubbies. And that system remains in use today.