Commonplace today, the zipper and button construction of blue jeans was a major innovation. Using the patent for the J.W. Davis and Levi Strauss innovation, individuals comb an image of the fly for clues. Afterward, they discuss its...

The National Museum of American History has assembled a collection of resources that underscore the significance of Lincoln's Gettysburg Address, including a draft of the speech in Lincoln's own hand, a video of the Lincoln Bedroom,...