"Ma'am" or "Miss" in American English? [closed]

Wikipedia offers the following:

The usage of "Miss" as a title in the United States is most frequently seen when referring to girls under eighteen. Though "Miss" is less commonly used as a title by unmarried adult women in the United States than in the past, some still prefer to be referred to as such. Twenty-first century etiquette honors an adult woman's personal preference of title. However, if the preference is not known, "[Miss]" is used. "[Miss]" is becoming the preferred choice as this female title in business. It is the equivalent to the male title "Mr." as neither is marital status specific.

Basically, the choice between these two honorifics has historically drawn from a woman’s age and marital status, but if you’re not sure you should probably use “Miss”.

^{On a personal note, I learned from working as a sales clerk that women with non-white hair almost universally prefer “Miss”. Sometimes it does not convey respect to imply that someone has earned it with their oldness.}

Miss is both common and proper. Ma'am is proper but not common. Ma'am has connotations of both older and higher status, Miss connotes younger and lower status. Since the sales-clerk is in a lower-status position vis-a-vis the customer, Miss is typical even when the clerk is older than the customer. Conversely, the clerk might address the customer as Ma'am. Miss is generally safe, because most people like to be thought of as young, even though it connotes a lower status.