At our writing disposal are a preponderance of short straight lines:
- Hyphen -
- En dash –
- Em dash —
- minus sign −
- Horizontal bar ―
- Figure dash ‒
From what I've read, the em﹘ and en−dashes—in particular originated with typography. What is not clear to me is why so many variations were they created. This post–which makes a case against using them‐suggests that the em-dash itself is of nebulous origin―at least in terms of time.
Usage has been covered on this site and others (e.g. When should I use an em-dash, an en-dash, and a hyphen?) , but ‑where did they all come from and why the need for so many short straight lines?