Since 1800, the full-length portrait of George Washington that hangs in the East Room of the White House has been viewed with suitable awe by hundreds of thousands of guests and tourists. In 1814 the picture became part of the American legendry when it was removed by the doughty Dolley Madison just before the British arrived to burn the place down. What is more, the painting is by that greatest of American portraitists, Gilbert Stuart.
Or is it? Marvin Sadik, director of the National Portrait Gallery, thinks not. Sadik argues that the painting was actually by William Winstanley, an English artist who...