The New York Public Library's Beaux-Arts Stephen A. Schwarzman Building celebrates its 100th anniversary this month on May 23. The Centennial offers a wonderful opportunity to reflect on Library use from the past 100 and uncover stories that can serve as inspiration for another century. One unique way to trace the history of the Library is through call slips. In order to use books in the research collection, patrons request specific titles by filling out a call slip, which includes the following information: author, title, and call number. Not all call slips have been saved over the years, but some have been preserved for posterity. Here are their stories.