In 2006, conservator Ralph Wiegandt flipped on his Zeiss Axio stereomicroscope and peered at the surface of an 1848 daguerreotype. The Cincinnati Public Library had entrusted him to clean its prize possession, a rare five-and-a-half-foot-long, eight-plate panorama photograph of the city’s waterfront. Working out of the George Eastman House in Rochester, New York, he found the image’s surface strewn with corrosive particles, as he had expected. But, at the same time, extraordinary details from the image jumped out at him: letters on a billboard, a face in a window. Black spots indeterminate to the naked eye magically resolved into wagons, groups of men, and laundry drying on a clothes line.

Eagerly, Wiegandt moved his microscope over to the Second Presbyterian Church’s clock tower in the panorama’s second plate. Librarians in 1947 had pinpointed the photograph’s date withmagnifying glasses and steamboat manifests to Sunday, September 24, 1848, but they couldn’t determine the time of day on the blurry clock face. Wiegandt adjusted the microscope, and the clock’s hands popped into focus: 1:55 p.m. No one had ever seen these details before.

An excited e-mail to the curators in Cincinnati set up further work, which involved snapping more than 11,000 high-resolution digital photographs of every inch of the daguerreotype. Each was blown up, uncovering even more detail as the examples on the following pages reveal. Some images were both idyllic and haunting: two boys with buckets walk along the river banks near an open sewer, hinting at the calamity to come when a devastating cholera outbreak killed nearly 6000 Cincinnatians between 1849 and 1851 and sent many residents fleeing for their lives. Would the boys become victims?

“We can read about living in a tenement or working on a riverboat, but it’s different if you can see it,” said Patricia Van Skaik, manager of the library’s Genealogy and Local History Department. Over the past five years, the curators and conservators have mined the image for visual details about the boomtown of Cincinnati, which was founded in 1788 and was exploding with commerce and innovation in the 1840s and 1850s, providing a snapshot of America coming into its own on the eve of the Civil War.

The Ohio River connected Pittsburgh to Cincinnati and—via the Mississippi—the international port of New Orleans. The steamships seen tied up in the photograph carried not only passengers but manufactured goods tomarket. In addition, the 300-mile Miami and Erie Canal, completed in 1845 at a cost of $8 million, connected the city to Toledo on Lake Erie (plate 6 shows a bridge over the canal). Unlimited quantities of anthracite coal brought by barge spawned many manufactories in the late 1840s: iron foundries, breweries, sawmills, rollingmills, finishing shops, bell and brass foundries, boiler yards, and boatbuilding and machine shops. As a result, Cincinnati’s population jumped 150 percent to 115,000 between 1840 and 1850. By 1850, a little more than 16,000 mostly brick buildings (up from 6781 in 1840) housed 91 churches, numerous factories and homes, and workplaces of 1676 tailors, 7864