The photo above is a daguerreotype – the first publicly announced type of photograph. The technology of its eponymous creator, Louis Daguerre, daguerreotypes were, relative to modern photography, slow. It took over ten minutes for a concoction involving silver halide and mercury (and a lens) to take the viewed scene and turn it into a photograph. Anything which moved out of the frame during this period would, by and large, be invisible in the finished product. For this reason, the early daugerreotypes — typically, streets of Paris (where Daugerre worked and lived) — lacked people, as they’d not stay still (or even know to) for the period necessary.
The first exception: the image above, of Paris’ Boulevard du Temple, taken in 1838. At the corner of the tree-lined street appears a man getting his shoes shined by a young man. (Can’t see it? Here’s a bigger version.) No one knows who the people depicted are, as at the time, the historic value of their identity was unappreciated. The daguerreotype would be used for portraits in the future. In fact, the first known photograph of Abraham Lincoln, seen here, was one.
Bonus fact: In 1851, a Prussian photographer used the daguerreotype method to take the first known photograph of a solar eclipse.
From the Archives: Foul Tip: How a photographer accidentally captured a small bit of obscene language on film — and also accidentally had it ending up appearing on a baseball card.
Related: The Scenic Daguerreotype: Romanticism and Early Photography by John Wood. Unreviewed on Amazon.