Ever since “Ms.” emerged as a marriage-neutral alternative to “Miss” and “Mrs.” in the 1970s, linguists have been trying to trace the origins of this new honorific. It turns out that “Ms.” is not so new after all. The form goes back at least to the 1760s, when it served as an abbreviation for “Mistress” (remember Shakespeare’s Mistress Quickly?) and for “Miss,” already a shortened form of “Mistress,” which was also sometimes spelled “Mis.” The few early instances of “Ms.” carried no particular information about matrimonial status (it was used for single or for married women) and no political statement about gender equality. Eventually “Miss” and “Mrs.” emerged as the standard honorifics for women, just as “Mr.” was used for men (“Master,” from which “Mr.” derives, was often used for boys, though it’s not common today). While “Miss” was often prefixed to the names of unmarried women or used for young women or girls, it could also refer to married women. And “Mrs.,” typically reserved for married women, did not always signal marital status (for example, widows and divorced women often continued to use “Mrs.”). The spread of “Ms.” over the past forty years both simplifies and complicates the title paradigm.
But the term goes back even further, as Ms. was used on a tombstone in 1767 for Ms. Sarah Spooner, which may be a case of saving room. Link -via TYWKIWDBI
Somewhere there's a bra burning...
It does stand for something: the fact that some women would prefer not to carry a title that refers solely to their status as the property of someone else.
Miss (first name) and Mr. (first name)
It is very common here in the south, even when I worked in daycare, for children to address adults in this manner. I believe it is more a term of respect towards ones elders than a term for a Fallen Woman. Considering the nuances of "southern hospitality", respect would be given even to "Miss Lilly's" face, though knowing nods would be passed behind her back.