Originally English speakers only used surnames a a first or middle names to honour specific people (usually a relative, but also a godparent or a famous person they admired). Eventually some of these names became "normal". Other people stared copying them either because they wanted to honour that person (e.g. "
Montgomery Smith", named after his mother's maiden name, is godfather to a baby
Montgomery), or they just used the name because they liked it, regardless of the original namesake(s). ). If you read 19th century English novels, you have many examples of this!
Many of the surnames used on girls are used because they look or sound feminine (especially if they end in -ey or -ly) or because they allow for feminine nicknames (
Madison,
Emerson,
Addison >
Maddie,
Emmie,
Addie; but people don't name their daughters
Jackson or
Jefferson!). Also sometimes a surname is similar to an already existing feminine name (e.g.
Reese can be short for
Therese;
Kelly can be short for
Cornelia /
Raquel).
Moreover, it is a relatively common phenomenon in the USA to give girls masculine names. If people feel comfortable naming their daughters
Alexis, it's no big deal to name them
Rylie or
Mackenzie.
A positive consequence, of course, is that sometimes this causes for feminine medieval names that only survived as surnames to be used on girls again.
Ellery,
Aubrey,
Emmett,
Averill were feminine names in Mediaeval England. (And names like
Julian,
Christian,
Bennett and
James were used for both genders).
Alexandrina, Annabella, Clementine, Charlotte, Emilienne, Florence, Frederica, Katharina, Mary (May), Maud, Penelope, Rosamund, Theodora (Teddy).
Aubrey, Axel, Benedict, Bertrand (Bertie), Cuthbert, Dashiell, Everard, John (Jack) Leopold (Leo), Magnus, Matthias, Maximilian (Max), Wilfred.This message was edited 6/13/2016, 2:10 PM