Fifteen years ago I was asked to write a book entitled Women Photographers at National Geographic and happened to mention the project to a colleague, a well-known male photographer then on the magazine staff. “Women photographers? It'll be a short book,” he said, flicking the notion away as if it were a bit of stray lint on his jacket sleeve. He was wrong. The book was substantial in size (271 pages) and in the number of women photographers featured in its pages (more than 40).

To be fair, he might be forgiven for thinking the way he did. The tally of women photographers at National Geographic, as at other magazines, has always trailed that of men. Fortunately, the gap has narrowed since the first woman, Kathleen Revis, was put on the photographic staff in 1953 (more about her later).

Unsurprisingly, parity was slow in coming. After Revis it would be 21 years until the next woman, Bianca Lavies, made her appearance on staff, followed three years later by Jodi Cobb.

In fact, the work of women photographers had appeared in fits and starts in the magazine long before Revis, through over-the-transom solicitations. There was, for example, Dorothy Hosmer, who had quit her job as a secretary, paid $89 for a third-class steamer ticket, and set off for a trip around the world. In 1937 Hosmer wrote the editors of the magazine from Florence — she was 26 years old at the time — and asked if they would be interested in publishing an “account of her trip with illustrative photographs”.

There were other women in those early years. The remarkable Harriet Chalmers Adams had 21 stories published in the magazine from 1907 to 1935, and although she is listed as an author in the National Geographic Index, an examination of her work shows that she took photographs as well. Adams, one of the first and few women correspondents of World War I, was an adventurer and explorer in the tradition of the intrepid 19th-century journalist Nellie Bly. Before her death in 1937, she retraced the trail of Columbus, crossed Haiti on horseback, and according to the New York Times, “reached twenty frontiers previously unknown to white women … [...]”

In 1953, the magazine hired its first woman staff photographer, Kathleen Revis, a quiet self-effacing woman who loved the outdoors, taught herself how to shoot pictures, and just happened to be the sister-in-law of the Editor, Melville Bell Grosvenor.

“Melville Grosvenor wanted to bring women to National Geographic,” says Mary Smith, the picture editor who handled most of Revis's stories. “He wasn't a bit afraid of smart women; he liked and respected them and as far as he was concerned, the smarter the better.” Let others grouse about favoritism. MBG pushed criticism aside. “It seems the boys thought it was some joke or I was nepotizing,” he wrote Revis, in response to the baritone-pitched grumbling. “My only comment was, ‘Well, boys, when you see a natural photographer, encourage him or her all you can!' Kathleen, you are a natural photographer. You not only have a feel for a picture but you love it, study it, and live with it … Keep on taking pictures. Try to tell a story in them.”

And that is exactly what every woman photographer hired by National Geographic has done since then.