Carrollton Viaduct
Carries	Two tracks
Crosses	Gwynn's Falls
Locale	Baltimore, MD
Owner	CSX Corporation
Design	Roman Arch Bridge
Longest span	80 feet (24 m)
Total length	312 feet (95 m)
Clearance below	51 feet, 9 inches (15.8 m)
Opening date	1829

The Carrollton Viaduct, located over Gwynn's Falls near Carroll Park in Baltimore, MD is the first stone masonry bridge built for railroad use in the United States. Today it is the world's oldest railway bridge still in use,  Viaduct, named after Charles Carroll of Carrollton, MD,  Mr. Carroll, the last living signer of the Delcaration of Independence, laid the cornerstone on  July 4, 1828. As he laid the first stone he said: "I consider this among the most important acts of my life, second only to my signing the Declaration of Independence."

The Baltiomre & Ohio Railroad contracted Caspar Weaver and James Lloyd to construct the structure. The bridge diemnsions,
 
Length: 312 feet (95 m) 
Height: 65 feet (20m) from its foundations 
Height to Railhead: 51 feet, 9 inches (15.8 m) above Gwynn's Falls.
Design:  Single Full-centered arch with a clear span length of 80 feet (24 m) over the stream, 
Width: Space for two railroad tracks on its deck. 
underpass for a wagon road, an arched passageway, 16 feet (5 m) in width, was built through one of the masonry-walled approaches.
The heavy granite blocks which form the arches and exterior walls were procured from Ellicott's Mills and Port Deposit. 
A white cornerstone at one end of the bridge bears the inscription "James Lloyd of Maryland, Builder A.D. 1829."

Andrew Jackson, the first President of the United States to ride on a railroad train, crossed the bridge on a trip between Ellicotts Mills and Baltimore on  June 6, 1833.