Race Riot, a silkscreen print by Andy Warhol, sold for $62.8m at Christie's major post-war and contemporary art auction in New York on May 13.
The piece shows a panel of four variations on a photograph, taken by Charles Moore during the Birmingham Race Riots in Alabama in 1963, that depicts local police setting their dogs on a civil rights protestor.
The public outcry that the image generated was key in forcing the Kennedy administration to set up the Civil Rights Act of 1964, which outlawed discrimination and ended racial segregation across the US.
The piece is one of only 10 such prints that Warhol produced, making it one of his rarer works, and stands at six feet across. It was created for his Death in America series, which explored US attitudes to violence.
Warhol's White Marilyn was another highlight, more than doubling its $18m estimate to make $41m (an increase of 127.7%).
The piece is among the artist's best-known treatments of the actress and is one of eight he produced for an exhibition at the Stable Gallery in 1962.
Laura Paulson, Christie's chairman of post-war and contemporary art, commented prior to the sale: "Compared to the perfectly coiffed media propagated publicity images of the actress, in White Marilyn she appears touched by humanity, and transcends reality to become a modern Saint."
The May 13 sale was the biggest auction in history, achieving total sales of $744.9m.
We have a strong range of Marilyn Monroe memorabilia available.
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