The BPL’s Anti-Slavery Collection—one of the largest and most important repositories of abolitionist material in the United States—contains approximately 40,000 pieces of correspondence, broadsides, newspapers, pamphlets, books, and memorabilia from the 1830s through the 1870s. These documents provide a firsthand perspective on a critical period in American history that resonates with current social and cultural movements. To complete the monumental task of transcribing the collection, the library has enlisted the help of thousands of online volunteers who pore over handwritten texts to create machine-readable content that will be tagged and indexed for future generations of researchers to discover.