How to Date an Old Photograph: Clues You Can Check at Home, and an Honest Range

The mount is stiff and slightly warped. A seated man in a tight collar stares past the camera. The back of the card is bare, so all you have is a face and a question about whose it is and what year it was taken.

It is often possible to narrow that down. Four sources of evidence are available at home: the thing itself, the studio, what the sitters wear, and the relatives who still remember. A lamp, some patience and a pencil are all the equipment you need.

First, a caution. One clue seldom produces a year. A range is the realistic result, and it shrinks each time another clue agrees.

Handle first, then look

A whole box is too much for one sitting. Select around twenty prints that puzzle you most, such as group portraits, unnamed faces and pictures of a house that matters, and spread them on a clean table with no food or drink nearby.

The US National Archives gives simple handling rules: wash hands and skip the lotion, and handle photographs and negatives with gloves, since fingerprints can stain them for good. Hold prints by the edges. Treat glass or metal pictures, such as tintypes, with extra care.

What kind of picture is it

Of all the evidence, the kind of print speaks loudest, since each had its own period. A talk from the National Library of Australia, on finding and dating photographs, walks through them. Its timings suit Britain and Australia, and your own country might differ by some years.

• A mirror-like image on metal in a small case is a daguerreotype, from the earliest years of photography, which began in the 1830s.
• An image on glass is an ambrotype, from the middle of the nineteenth century. Each is a one-off.
• A dark image on thin iron is a tintype, at its peak in the 1860s and 1870s.
• A small portrait pasted onto a card is a carte de visite, which appeared around 1859.
• A larger portrait on a stiffer card is a cabinet card, common later in the 1800s.
• A photograph printed on postcard stock belongs to the early 1900s.

Roll film altered everything again. The Brownie camera of 1900 made snapshots cheap, so an informal picture with white margins and no studio furniture is more probably a twentieth-century family snap than a studio sitting. Early cartes de visite are thin and plain, and later cards are thicker with fancier borders, which you can feel when you hold two side by side.

Turn it over

• The studio stamp. Plenty of mounts print the photographer's name and town. If you can find when that studio opened and closed, you have hard limits: the picture falls between them. The New York Public Library's Photographers' Identities Catalog is a research tool for tracing photographers, mainly useful for American studios. Local libraries and trade directories help elsewhere.
• Printed details. Postmarks, stamps and brand names can shrink the window.
• Handwriting. A pencilled name and date is a lead and never proof. Test it against the process and the clothing.

Read the clothes and the room

Clothing changes quickly and reads more easily than most people assume. The Australian talk offers markers for its own world: crinolines in the 1850s, bustles in the 1880s, cloche hats in the 1930s. Three habits prevent errors. Study the youngest grown woman, because she follows the newest style while older sitters lag behind. Check men's cravats and watch chains, which shifted often. And never infer a toddler's sex from a frock, as boys and girls alike wore them into the 1920s.

Next, the setting. Studios relied on props and painted scenery, so a painted garden behind a fence points to a studio while a plain kitchen door points to home.

An invented example

Take a made-up case. A family owns a cabinet card of a seated man, unnamed, with only a studio stamp. A town archive says that studio worked from 1871 to 1889. His collar and whiskers fit the 1870s. An elderly aunt recalls a great-uncle who moved abroad in 1878. The note could read "between 1871 and 1880, possibly before the great-uncle emigrated". It is honest and it shows its working.

Ask relatives one at a time

Paper evidence only goes so far. Show the print to a few relatives one by one, so they cannot talk each other into a single answer. Ask what they notice, who they think it is and what was happening then. Note every reply under the speaker's name, and keep conflicting ones side by side. Faces no one can name have their own guide: naming the unknown people in old pictures. Letters and clippings sometimes pin a date down too, as old papers as memory joggers explains.

A range beats a year, and a sleeve beats the back

Many family archives settle on whichever year someone guessed first and move on. In our view that is the worst result. A confident wrong year, repeated for twenty years, hardens into family fact. Record a range, the evidence, and who offered each clue, and leave the question open for whoever looks next.

On annotation, the Library of Congress advises against writing on photographs if you can avoid it, and otherwise recommends a soft graphite pencil near the back edge. We would stop short of marking the print at all. A note on the sleeve, on a card beside it, or in a file costs next to nothing and leaves the print as it was. Relax the rule only for a spare copy nobody will miss.

Record it and keep it safe

For every picture, jot the range, the evidence and its source, for instance: "1871 to 1880. Cabinet card, studio dates, collar style, Aunt Lea's story." Scan both sides, put the range in the file name (Unknown-man_studio-portrait_1870s-approx.jpg works), and store two copies in separate places. Organizing photos by family has a naming system. A private home such as Glow can hold the picture, the clues and the voices of the relatives who helped, and a shared folder with a notes file is a fine alternative.

The whole project, from dating through scanning to backup, is laid out in the preservation guide, and the scanning step has its own page on scanning old family photos.