In reality, many of the "witches" over the years were medicine women, midwives, or those who lived outside of the prescribed social order of their time.
The "existence" of witches goes back as far as biblical times based on stories and myths. These tales, however, have their origins in women just being simple merchants.
So you love Harry Potter, and dreamt of going to Hogwarts, but your letter never came. Now you can attend a different sort of wizarding school located in Central Texas.