American History TV visited the Smithsonian's National Museum of American History for a look at the newly opened First Ladies exhibit. See inaugural and evening gowns, including those worn by Dolley Madison, Mary Lincoln, Jacqueline Kennedy, Pat Nixon and Michelle Obama. Curator Lisa Kathleen Graddy explains what these gowns have to tell us about the unofficial yet influential role first ladies play in presidential administrations – and about the politics and culture of their times.