This work offers a sweeping collection of A–Z entries and primary source documents that presents a thorough examination of all the individuals, groups, and events surrounding the 9/11 terrorist attacks. Commemorating the 10th anniversary of the attacks on the World Trade Center and Pentagon, The 9/11 Encyclopedia: Second Edition offers valuable perspective on this emotionally charged and multidimensional subject. This comprehensive two-volume encyclopedia details the events leading up to the attacks, going back a decade prior to 9/11, and covers all the major players involved. It also examines events and discoveries since 2001 that have influenced our understanding of—and reactions to—the world-changing attacks. In the second edition, dozens of entries have been updated and many new ones added. The documents volume has been expanded as well. With more than 170 A–Z entries, dozens of descriptive sidebars, and over 55 primary-source documents, this updated encyclopedia is an essential source for comprehending one of the darkest moments in American history.