Industrial History: 1829 B&O Patterson Viaduct over Patapsco River at Ilchester, MD

Baltimore & Ohio Ellicott City Station Museum posted

On Dec. 4, 1829, the Patterson Viaduct was ceremonially opened. The viaduct was the second of the main bridges to be built on the first 13 miles of the Baltimore and Ohio Railroad between Baltimore and Ellicott's Mills. The Patterson Viaduct spans the Patapsco River at Ilchester and, like the Ellicott City Station, it was built from locally quarried granite. The viaduct was named for William Patterson, the Irish-born merchant who was known as one of the wealthiest men in Baltimore. Patterson was one of the founders of the Baltimore and Ohio Railroad.

The Patterson Viaduct would stand until 1866, when it was damaged by flooding. Sadly, all but one of the original spans of the Patterson Viaduct was destroyed in the Great Patapsco Flood of 1868. In the aftermath, the B&O would replace the stone spans with a Bollman iron-truss bridge. In 1902, the Patterson Viaduct was bypassed when the B&O finished realignment work following the completion of the nearby Ilchester tunnel and rail bridge.

Today, you can still cross the Patterson Viaduct. Since 2006, a footbridge has sat on the original abutments of the Patterson Viaduct, marking the beginning of the Patapsco State Park’s Grist Mill Trail.

Image: The Patterson Viaduct in 1841

Conor Conneally shared

David Andrew Wieting: All of the early important bridges were named for B&O stockholders and officials. A single arch of the Oliver Viaduct still exists at Ellicott City and carries the OML Subdivision to this day.

The towers of the replacement suspension bridge are peaking over the tops of the trees. And we can see the far original bridge abutment.