Please tell me more about the significance of this figure.
It is a figure of "Victory" and was cast from the fourth version of Augustus Saint-Gaudens's memorial to Colonel Robert Gould Shaw, commander of the Massachusetts Fifty-fourth—the first black regiment raised in the North and best remembered for its assault on Fort Wagner, North Carolina, in 1863.
On dedication day of the original memorial in Boston in 1897, Booker T. Washington proclaimed that "the full measure of the fruit of Fort Wagner and all that this monument stands for will not be realized until every man covered with a black skin shall by patient and natural effort, grow to that height of industry, property, intelligence and moral responsibility, where no man in all our land will be tempted to degrade himself by withholding from his black brother any opportunity which he himself would possess. Until that time comes, the monument will stand for effort, not victory complete."
What does this work symbolize?
This is a copy of a winged figure from Augustus Saint-Gaudens' Memorial to Robert Gould Shaw and the Massachusetts 54th Regiment in Boston.
This angel is an allegorical figure representing "glory," and it flies over Robert Gould Shaw (seated on horseback) in the full memorial. It signifies the valiant behavior of the regiment but it also grieves for the lost soldiers.
Who is the artist?
That was made by Augustus Saint-Gaudens (who also sculpted the statue of Lincoln in the center of the room).
The angel holds two symbolic objects: poppy flowers, traditional symbols of death and remembrance, and an olive branch, symbolizing victory and peace.