I first heard about this on the Enquirer's website today, but in the comments section someone pointed me to the Wired.com article about it, which is so much better.
In 1848, Charles Fontayne and William Porter produced one of the most famous photographs in the history of the medium — a panorama spanning some 2 miles of Cincinnati waterfront. They did it with eight 6.5- by 8.5-inch daguerreotype plates, a then-new technology that in skilled hands displays mind-blowing resolution.
Fontayne and Porter were definitely skilled, but no one knew just how amazing their images were until three years ago, when conservators at George Eastman House in Rochester, New York, began restoration work on the deteriorating plates. Magnifying glasses didn’t exhaust their detail; neither did an ultrasharp macro lens. Finally, the conservators deployed a stereo microscope. What they saw astonished them: The details — down to window curtains and wheel spokes — remained crisp even at 30X magnification. The panorama could be blown up to 170 by 20 feet without losing clarity; a digicam would have to record 140,000 megapixels per shot to match that. Under the microscope, the plates revealed a vanished world, the earliest known record of an urbanizing America.
Head over to Wired and check it out. These photo's are the earlier known to show a steamboat and railroad station. It is also one of the earliest photo's known to show free African Americans.