Almost as soon as the first photographs came out of cameras, people were using them to manipulate images.
Take, for example, the very famous portrait of Abraham Lincoln, standing with one hand on his desk. Analysis in the 20th century showed that his mole was on the wrong side of his face, and further research turned up a picture of North Carolina Congressman John Calhoun in exactly the same pose. Someone in the 1860s had taken Lincoln's face and pasted it onto Calhoun's body, and the resulting fake photo was spread all across the Union.
Through the Civil War, photo staging was much more common than photo editing. It was very difficult to get an "action" shot because of the long exposure times, so war photographers would pose their shots.
Later, through the early twentieth century, photo postcards showing monstrous fish, grasshoppers, and crops were very famous, and nearly all of them were made by merging two shots into the same frame. As the Dust Bowl ruined crops, the postcards of apples the size of watermelons and corn cobs as big as fireplace logs showed a very dark humor, almost a sick joke.
Josef Stalin made photo editing famous, as those who fell out of favor simply "ceased to exist." There are numerous examples of pictures where people standing beside him have simply been painted out and forgotten.
Even magazines and newspapers today are not immune. One magazine over-darkened OJ Simpson's mug shot for it's cover, making him appear much darker and more menacing than he was in real life. And a number of photojournalists were caught using Photoshop tools on their photos to either merge two scenes into one or increase the smoke and battle damage far beyond what was really there.
Photo faking goes beyond simply posing a scene, because it's a blatant attempt to lie to the viewer.