The Greek Slave: The Most Popular Work of the mid 19th Century?

The Greek Slave, by Hiram Powers 

(photographs by Jim Potts, at The Phillips Collection, DuPont Circle, Washington, DC).

Elizabeth Barrett Browning: Sonnet, "Hiram Power's Greek Slave"

They say Ideal beauty cannot enter
The house of anguish. On the threshold stands
An alien Image with enshackled hands,
Called the Greek Slave! as if the artist meant her
(That passionless perfection which he lent her,
Shadowed not darkened where the sill expands)
To so confront man's crimes in different lands
With man's ideal sense. Pierce to the centre,
Art's fiery finger! - and break up ere long
The serfdom of this world. Appeal, fair stone,
From God's pure heights of beauty against man's wrong!
Catch up in thy divine face, not alone
East griefs but west,- and strike and shame the strong,
By thunders of white silence, overthrown

National Portrait Gallery, DC: