The Carrollton Viaduct

From the U.S. Army Corps of Engineers, Headquarters:

#OTD: In 1829, the world's first stone masonry railroad bridge -- the Carrollton Viaduct -- was completed in Baltimore.

The bridge is named for Charles Carroll, signer of the Declaration of Independence and who had been present on July 4, 1828 to help break ground for the project. Originally built by the Baltimore and Ohio Railroad with good, strong Maryland granite, the bridge is still in active use carrying loads well in excess of the early B&O trains.

The bridge became a National Historic Landmark in 1971, and the American Society of Civil Engineers named it a Historic Civil Engineering Landmark in 1982.