Abigail is an Old Testament name—she was the wife of David, renowned for her beauty, wisdom, and prophetic powers—that became a term for a maid in the early nineteenth century, which led to a fall from favor. Now, Abigail's back in a big way—it's Number 8 on the 2016 list, which is right around where it's been for several years in a row—liked for its slightly proper vintage charm.
Abigail has been the name of two of our First Ladies—three, if you count the character on The West Wing—and Abby has been the name of a host of television and movie characters—she has been seen on screen in everything from Mad Men to The Lovely Bones.
Abigail's biblical roots and her sensible image combined with cute, accessible nickname Abby make her popularity understandable.
If you like Abigail but want something fresher, you may consider such other biblical choices as Lydia and Priscilla or names popular in Revolutionary Era America that have been neglected in recent years, such as Susannah and Eliza.