In the 1980s, while conducting research for the book, Classics of American Architecture: The World Trade Center, I was invited to pour through the contents of the World Trade Center archives kept at the Port Authority library, on the 55th floor of Tower One. The archivists kindly permitted me to make copies of anything that seemed useful. When preparing the new edition (2012), I went back though my files and found some 500 pages of documents. Some of these now form the appendix to the new edition. The others I will gradually scan and upload here – with the express permission of the Port Authority – as a kind of virtual archive.