John T. Daniels; Charles Levy Arthur; Tsang Hin Wah; NASA; Lewis Hine; Joe Rosenthal; John Dominis;Sam Shere // Getty Images In an era where any novice with a smartphone can take professional-quality photographs, suffice it to say people are taking a lot of pictures. By one estimate, nearly 2 trillion photographs are captured each year–and more than 55,000 every second around the world. Although photographs have become ubiquitous in an age of selfies and social media, they still possess their timeless power to transport us to faraway places, introduce us to compelling people, and–in many instances–even alter the course of history. Stacker collected 25 examples of images that changed the course of history, whether by advancing technical abilities of photography that enabled more people to engage in it, or by recording moments, items, people, and events that were made more significant because there were images for people to share. Prior to its widespread use, photography was a technological puzzle. The effort involved chemistry, physics, metallurgy, and all manner of optical devices. Over the years, the equipment got smaller, lighter, and easier to use. By the late 1970s, tens of millions of cameras were sold around the world every year. Since then, the advent of digital photography and the spread of the aforementioned camera-equipped smartphones have put cameras into the hands of more than two of every three people on the planet, according to an industry analysis by Statista. Photographs and the people who make them have helped billions of people better understand our world and what lies beyond it. Keep reading to discover 25 images that helped shape human perception and understanding of the last 200 years. View from the Window at Le Gras – Joseph Nicéphore Niépce (c. 1827) Joseph Niepce // Getty Images The oldest surviving photograph ever taken took eight hours to expose and shows a view of buildings and trees from a window on the photographer Joseph Nicéphore Niépce’s estate. It marked the beginning of a technological and chemical revolution that led to several other methods of registering images based on chemical reactions that occurred when light hit a specially prepared surface. Boulevard Du Temple, Paris – Louis-Jacques-Mande Daguerre (1838) GraphicaArtis // Getty Images Made by Louis-Jacques-Mande Daguerre, this daguerreotype–an image printed on a silvered copper plate–is believed to be the first photographic image including a living person. Because of the long exposure time required, what would have been a bustling street appears empty except for a person standing still in the lower left, getting his shoes shined by a crouching figure. Lower Falls, Yellowstone National Park – William Henry Jackson (1871) William Henry Jackson/Library of Congress/Corbis/VCG via Getty Images William Henry Jackson captured this striking image of the Lower Falls while on an expedition to explore northwestern Wyoming. Reports of what Jackson’s group found–geysers, waterfalls, and other geologic wonders–were so incredible the public didn’t believe them until photographic proof was made available. Jackson’s photographs of the Lower Falls and other natural wonders in the region helped persuade Americans and Congress to create Yellowstone National Park, the world’s first national park. The Horse in Motion – Eadweard James Muybridge (1877) SSPL // Getty Images This set of photographic images truly paved the way for the film industry. Eadweard James Muybridge’s photos froze time in increments of 1/500th of a second. The photographer achieved this feat by capturing a series of images triggered on separate cameras by tiny threads broken by a moving animal or clockwork system. In addition to settling a controversy of the time–whether a horse ever lifted all its legs off the ground when galloping–Muybridge’s work showed people the value of viewing sequences of images taken at short intervals. Lodgers in Bayard Street Tenement, Five Cents a Spot – Jacob August Riis (1889) Jacob A. Riis/Museum of the City of New York // Getty Images Jacob Riis was an early investigative photojournalist whose 1890 book “How the Other Half Lives” documented the lives of people who lived in the slums of New York City. The book exposed the squalor of the city’s tenement dwellings, including this room less than 13 feet long that was home to 12 men and women. The image sparked an investigation into housing conditions and is widely credited with sparking significant social reforms. Riis’ legacy is that of being among the first to energize a social movement using photography. The Wright Brothers First Flight – John T. Daniels (Dec. 17, 1903)