Union Arch Bridge, Stone arch bridge in Cabin John, United States
The Union Arch Bridge spans 140 meters across the valley, carrying both water from the Potomac River and vehicular traffic on MacArthur Boulevard.
Lieutenant Montgomery C. Meigs of the United States Army Corps of Engineers supervised the construction of this bridge from 1857 to 1864.
The bridge features dedication plaques that reflect the political changes during the American Civil War, including the controversy over Jefferson Davis's name.
The structure maintains its dual function as part of the Washington Aqueduct system while accommodating cars and pedestrians with protective barriers.
From 1864 to 1903, this granite and sandstone bridge held the record as the longest single-span masonry arch in the world.
Location: Montgomery County
Inception: 1857
Architects: Montgomery C. Meigs, United States Army Corps of Engineers
Length: 140 m
Made from material: granite, sandstone, dimension stone
Part of: Washington Aqueduct
GPS coordinates: 38.97290,-77.14800
Latest update: September 23, 2025 16:45
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