Below are a few example images from the website FourandSix.com, which is a company that was co-founded by one of the pioneers of Adobe Photoshop: Kevin Connor. They specialize in debunking altered photos and here are a couple ones that show photo manipulation was available over 150 years ago!
This print (Library of Congress, Prints & Photographs Division) appears to be of General Ulysses S. Grant in front of his troops at City Point, Virginia, during the American Civil War. Some very nice detective work by researchers at the Library of Congress revealed that this print is a composite of three separate prints: (1) the head in this photo is taken from a portrait of Grant; (2) the horse and body are those of Major General Alexander M. McCook; and (3) the background is of Confederate prisoners captured at the battle of Fisher’s Hill, VA.
In this doctored photo of Queen Elizabeth and Canadian Prime Minister William Lyon Mackenzie King in Banff, Alberta, King George VI was removed from the original photograph. This photo was used on an election poster for the Prime Minister. It is hypothesized that the Prime Minister had the photo altered because a photo of just him and the Queen painted him in a more powerful light.
It is believed that this doctored photograph contributed to Senator Millard Tydings’ electoral defeat in 1950. The photo of Tydings (right) conversing with Earl Browder (left), a leader of the American Communist party, was meant to suggest that Tydings had communist sympathies.
This nearly iconic portrait (in the form of a lithograph) of U.S. President Abraham Lincoln is a composite of Lincoln’s head and the Southern politician John Calhoun’s body.
In this doctored photograph, Adolf Hitler had Joseph Goebbels (second from the right) removed from the original photograph. It remains unclear why exactly Goebbels fell out of favor with Hitler.