What are the 100 most influential photographs? To answer this question, Time magazine reached out to historians, curators, and photo editors and conducted interviews with photographers, subjects of famous photographs, and others to assemble this collection of photographs taken between 1826 (when the first known photograph was taken by Joseph Nicephore Niepce) and 2015. Each selected photograph is accompanied by a short essay. These photographs, which can be browsed chronologically, vary widely. Some are poignant, while others are whimsical. Visitors, especially educators and parents, should be aware that some of these photographs depict violence and human suffering and may be disturbing. There is also a series of short documentary films, Behind the Photographs, that provide additional context to some of these famous images.