On their website, Proquest describe the Vogue Archive as:
an exclusive partnership between ProQuest, Vogue, and Condé Nast (the global publisher of Vogue) to present the full run of the American Vogue, 1892 to present, for the library market. Every page, cover, advertisement, image, and fold out is indexed, searchable, and viewable in beautiful high-resolution color.
More than 400,000 pages are included, constituting a treasure trove of the work from the greatest designers, photographers, stylists and illustrators of the 20th and 21st centuries. The Vogue Archive is both an essential primary source for the study of fashion and a unique record of American and international popular culture.
You can find out more at the Proquest website.