Daniel Chester French's "Memory"
Done by the same sculptor who created the Lincoln Memorial.
Fun factoid: the model (Audrey Munson) was featured on the U.S. Mercury Dimes, Walking Liberty half dollars (circa 1916), and on the present day Silver Eagle dollars.
UPDATE: A couple of my Daniel Chester French photos were featured on the Chesterwood website (historic conservation organization at French's former home/studio in Massachusetts). Very cool!