Most Influential Photos

We began this project with what seemed like a straightforward idea: assemble a list of the 100 most influential photographs ever taken. If a picture led to something important, it would be considered for inclusion. From that simple concept flowed countless decisions. Although photography is a much younger medium than painting–the first photo is widely considered to date from 1826–the astonishing technological advances since its beginning mean that there are now far more pictures taken on any given day than there are canvases in all the world’s galleries and museums. In 2016 alone, hundreds of billions of images were made.

How do you narrow a pool that large? You start by calling in the experts. We reached out to curators, historians and photo editors around the world for suggestions. Their thoughtful nominations whittled the field, and then we asked TIME reporters and editors to see whether those held up to scrutiny. That meant conducting thousands of interviews with the photographers, picture subjects, their friends, family members and others–anywhere the rabbit holes led. It was an exhaustive process that unearthed some incredible stories that we are proud to tell for the first time. You’ll find a selection in the pages ahead. The complete collection can be found in TIME’s new book, 100 Photographs: The Most Influential Images of All Time, as well as on our multimedia site time.com/100photos, where you can view original documentary films about key works.

See the 100 most influential photos of all time here

There is no formula that makes a picture influential, and a list about influence necessarily leaves off its fair share of iconic pictures and important photographers. A survey class in great photographers would surely include Ansel Adams. And yet no single one of the pictures Adams took inside Yosemite–majestic as they are–could rival in influence Carleton Watkins’ work, which led to the creation of the park. Some images are on our list because they were the first of their kind, others because they shaped the way we think. And some made the cut because they directly changed the way we live. What all 100 share is that they are turning points in our human experience.

Photography was born of a great innovation and is constantly reshaped by new ones. So it is fitting that our definition of an influential photo changes along with the ways pictures are taken and seen. The world first saw Abraham Zapruder’s haunting images of John F. Kennedy’s assassination not as a moving picture but as a series of frame-by-frame stills published in LIFE magazine. Before televisions were in every home, the photos that ran in LIFE influenced how a lot of people understood their world. When Philippe Kahn rigged his cell phone to take a picture of his newborn daughter nearly 20 years ago, he could scarcely imagine that his invention would change the world.

Now everyone is a photographer, a publisher and a consumer. This has largely been to the good. Our connection with photography is more personal and immediate than ever–that it took several days and multiple flights for Robert Capa’s pictures of the D-Day landings to see the light of day seems impossible when today our social-media feeds are bursting with images from every corner of the globe. But the digital revolution has made quantifying influence a particular challenge. Likes and shares are a very real metric, but are they enough? And what of a picture that was never published in a traditional way? Unless you are in viral marketing, there is nothing to admire in the poorly framed, celebrity-packed selfie organized by Ellen DeGeneres at the Oscars in 2014. Yet the photo’s astounding reach through social media makes it one of the most seen images of all time.

In the process of putting together this list, we noticed that one aspect of influence has largely remained constant throughout photography’s nearly two centuries: the photographer has to be there. The best photography is a form of bearing witness, a way of bringing a single vision to the larger world. That was as true for Alexander Gardner when he took his horse-pulled darkroom to the Battle of Antietam in 1862 as it was for David Guttenfelder when he became the first professional photographer to post directly to Instagram from inside North Korea in 2013.

James Nachtwey–the photographer who made the deeply moving image Famine in Somalia, among many, many others–has dedicated his life to being there. As he puts it, “You keep on going, keep on sending the pictures, because they can create an atmosphere where change is possible. I always hang on to that.”

See the 100 most influential photos of all time here