Penmanship is fast becoming a lost art. Unfortunately, it was a relatively short-lived phenomenon. There was really very little innovation with regard to writing instruments from the quill, until the mid-19th century. Iridium and steel were understood enough to start making dip pens that people could actually write with that would lay down a consistent line. I've tried to research the motivation behind the sudden explosion in penmanship. I haven't really found much on it. So, if anyone does know what the thinking was, I would really appreciate hearing from you. My guess is that it was the combination of the development of metalurgy and the social progress in general that demanded legible documentation.
But, whatever the reasoning, there was a virtual explosion of schools of penmanship, to the point that we now refer to the period from about the 1850s to the 1920s the "Golden Age of American Penmanship".
I personally came to be interested in it as a historian and linguist. In trying to learn Meso American indigenous languages and writing them phonetically during the Spanish colonial period, I became fascinated by paleography, the study of penmanship, in essence. We had to learn what 16th century Spanish handwriting looked like. The letters were actually different enough that if one didn't study the paleography, you would have no clue what the documents said, even if they were written in modern English.