Not an official site, but this Flickr user has collected together a display of photographs that have won the Pulitzer Prize. Easier to browse then the official Pulitzer Prize website, but less information--so check both.
Digital image library offering searchable collections of images and descriptive information including architecture, painting, sculpture, photography, and more, encompassing many time periods and world cultures.
Browse the Stacks!
A great way to find an iconic photograph is to browse the stacks. Most photojournalism books are located in Rose Library.
TR624-835 Applied photography (Including artistic, commercial, medical photography, photocopying processes)
Full online text and images for back issues of selected scholarly journals and monographs in history, economics, political science, anthropology, sociology, literature, etc.
*Temporary expanded access beyond JMU subscriptions is available until June 30, 2020. Use this link for a list of resources: https://about.jstor.org/covid19/expanded-access-to-collections/.