From the reading desk
How to trace an archival image to its source
Keep a usable trail from an image to its item record, creator credit and rights statement when researching historical pictures.
Keep the item record, not just the image
A downloaded file is only part of a research trail. Save the permanent item URL, catalog title, institution and record identifier when one is supplied. Record the image you actually used, including a restoration or presentation version identified by the source.
Separate the roles
The maker, publisher, digitizing institution and current holding archive can be different. Copy the source’s own role labels. In each Then & Found story, the picture credits and original-record links are kept alongside the discussion so you can return to the underlying evidence.
Read the item’s rights information
Follow the rights link supplied for the specific item and retain its wording. The Library of Congress explains that its holdings can have different rights conditions and that it does not own every image it preserves. A rights advisory describes the institution’s information; avoid rewriting it as a blanket promise about every possible reuse.
Leave a trail another reader can follow
A useful research note combines the caption, maker credit, date wording, source link and rights link. Explain any editorial crop or transcription separately. If an attribution remains uncertain, say so and link the record that preserves that uncertainty. Source attribution does not imply institutional endorsement.
Sources for the method
Prepared for Then & Found with AI assistance. Sources inform the methods; their institutions do not sponsor or endorse this guide.
Records to investigate
Photography and archival custody · 1868–1871 / 1981
John Thomson’s Hong Kong photographs
John Thomson travelled through China between 1868 and 1872, photographing streets, landscapes and people for audiences who would usually encounter them in print. Working with wet-collodion glass negatives meant carrying fragile equipment and preparing plates near the place of exposure. The tea-house view comes from Hong Kong during those journeys. Its later history is almost another journey: the negatives entered Henry Wellcome’s collection in 1921, and a contact print was made in 1981. The scene, the glass negative and the later sheet of photographic paper each have their own date.
3 books to explore · 3 records
Cities & construction · 1930s
San Francisco before the bridges opened
In July 1935, an aerial camera recorded San Francisco while two enormous bridge projects were changing its relationship with the surrounding bay. The Bay Bridge would open in 1936; the Golden Gate Bridge followed in 1937. Until then, crossing the water depended heavily on boats and ferries. From above, the city’s street pattern meets a shoreline shaped by piers, shipping and construction. This Navy photograph, later preserved in the NASA Ames archive, captures the interval when the new crossings were taking shape but had not yet become everyday routes.
3 books to explore · 1 record
Routes & transport · 1860s
The railroad meeting at Promontory Summit
Two locomotives faced one another at Promontory Summit, Utah, on May 10, 1869, as people crowded together to celebrate the meeting of the Central Pacific and Union Pacific railroads. Andrew J. Russell’s photograph helped turn that ceremony into a national image. Behind the posed gathering lay years of surveying, grading, tunneling and track laying, including the work of thousands of Chinese laborers on the Central Pacific. The railroad changed travel and commerce across the West, while its construction also brought land disputes, government subsidies and profound consequences for Indigenous communities.
3 books to explore · 1 record