This year a freshman at Miami University in Ohio discovered a rare fingerprint from Abraham Lincoln just barely visible on one of his letters housed within the college’s archives. Lydia Smith, now a psychology major, made the discovery in November 2008 while examining a letter that Lincoln wrote on October 5, 1863. John Lupton, director of the Papers of Abraham Lincoln Project in Springfield, has verified the finding. Though there is some debate over how many known Lincoln fingerprints exist (see this post from Sam Wheeler), Lupton claims this is actually the second one in the Miami University collection and one of several that probably exist –most because of smudge marks in nineteenth-century ink but some, such as this one, imprinted on the rag paper. Read various news stories about this discovery or see a terrific YouTube video that details the whole episode.