In 1919 a returning World War I veteran named Harry Hahn and his French bride attempted to sell what they thought was a painting by Leonardo Da Vinci in New York. Renowned art dealer Sir Joseph Duveen declared the picture-La Belle Ferronni?re-a fake without ever seeing the canvas. The Hahns
sued Duveen for slander, setting off a legal battle that would last for decades.
In The American Leonardo, John Brewer traces the twisting path of the Hahn...