Sources covering multiple countries

ARTstor
Collection of high quality images from academic institutions and museums. Note that the advanced search options allow you to limit by date of the object and by “classification.” For this project the most useful classifications will be “Photographs” and “Decorative Arts, Utilitarian Objects and Interior Design.”

Images of Colonialism
Late-19th- and early-20th-century trade cards and illustrations offering insight into European perspectives on the colonial experience. From Harvard.

International Mission Photography Archive
Historical images from Protestant and Catholic missionary collections covering from mid-19th century to mid-20th century “The pictures document indigenous peoples’ responses to missions and the history of indigenous churches which are often now a major force in society.” Hosted by the University of Southern California Libraries.

Image Collection of the German Colonial Society
Large collection of photographs from the colonial period in Africa. To better understand the collection, read the full description.

Trove
Images from cultural heritage collections around Australia as well as from individuals. Created by the National Library of Australia. Note that the photos included cover the world, not just Australia.

World Digital Library: Prints, Photographs
Images from cultural institutions around the world. A joint project of the Library of Congress and UNESCO.

Algeria

Gallica
Bibliothèque nationale de France digital library of texts and images from the Middle Ages to the early 20th century. Choose the Advanced Search option to limit your results to images.

Australia and New Zealand

Photographic Archive: National Library of New Zealand
Visual record of the land and peoples of Aotearoa New Zealand and the Pacific from the 1840s to the present.

Photography Collection: Museum of New Zealand (Te Papa)
Collection that includes historical documentary photography of New Zealand with strengths in early images of Maori and Pacific peoples. Note that after you do a search, you have to limit to the photography collection.

Korea

East Asia Image Collection
Collection of images documenting the history of imperial Japan (1868-1945), its Asian empire (1895-1945) and occupied Japan (1947-52). Includes images of Korea.

Southeast Asia Visions
Collection of written and photographed experiences of Europeans and Americans who traveled to Southeast Asia during the period of imperialism. From the Cornell University Library.