
The Maryland Chapter of the American Society of Civil Engineers will dedicate a plaque Saturday to honor the Thomas Viaduct in Elkridge as a National Historic Civil Engineering Landmark.
The Thomas Viaduct is the first multi-span masonry railroad bridge built on a curving alignment in the United States. The 612-foot-long viaduct, completed in 1835, stands 59 feet above the Patapsco River and Patapsco Valley, and is “a crucial part of Maryland’s rail infrastructure, carrying passenger and freight trains,” according to a news release from the American Society of Civil Engineers.
The group recognizes historically significant civil engineering projects, structures and sites worldwide. Nearly 300 projects have earned the title of National Historic Civil Engineering Landmarks “for their creativity, innovation, and challenging conditions in which they were built,” the news release stated.
The dedication will take place at 11 a.m., Saturday in Pavilion 104 at Patapsco Valley State Park, 6113-6117 River Road, Elkridge.

Founded in 1852, the American Society of Civil Engineers represents more than 150,000 civil engineers worldwide and is America’s oldest national engineering society. The group “works to raise awareness of the need to maintain and modernize the nation’s infrastructure using sustainable and resilient practices, advocates for increasing and optimizing investment in infrastructure, and improve engineering knowledge and competency,” according to the news release.