The role of the First Lady carries a lot of responsibility, but it's really more custom than law. How has is changed over time, and who are the women who have defined the role? Susan Swain is co-CEO of C-SPAN. She was the host of their year-long series "First Ladies: Influence and Image" and editor of the accompanying book. She's also behind the @firstladies Twitter feed.

The role of the First Lady carries a lot of responsibility, but it's really more custom than law. How has is changed over time, and who are the women who have defined the role?

Susan Swain is co-CEO of C-SPAN. She was the host of their year-long series span.org/">"First Ladies: Influence and Image" and editor of the accompanying span.org/FirstLadiesBook.aspx">book. She's also behind the @firstladies Twitter feed.