Is there a secret message in President Lincoln’s watch? Where’s the missing star from the Star-Spangled Banner? Explore these mysteries and more in Decoding History, a free virtual field trip to the Smithsonian’s National Museum of American History presented by Scholastic’s The 39 Clues Reading Club on March 5, 2013, at 1:00 p.m. (ET), 10:00 a.m. (PT).