Photography is a relatively recent invention. Although the first true photograph as we know it was taken roughly 200 years ago, that's obviously just a tiny slice of recorded history. For all of those "lost years," historians have had to get creative in reimagining famous historical figures. Though photography grew increasingly prolific after its invention, there's a sort of twilight period when historical figures were actually photographed, yet the rare photos aren't that well known.
These real pictures of historical figures like John Quincy Adams, Harriet Tubman, and Billy the Kid can give a whole new perspective on when these people lived. The fact that they're preserved on camera is mind-blowing. Vote up the images of historical figures you're most surprised to see exist.