Dolley Madison was eight years old when the Declaration of Independence was signed, and 40 when her husband James became president. In her late 70s she sat for a photograph, becoming the first (former) first lady to do so. Then, this summer, the National Portrait Gallery acquired it.In this mini 'Blink' episode, Kim speaks with Ann Shumard, senior curator of photographs, to hear how this rare daguerreotype came to light and how the Gallery was able to buy it.See the photograph here.