Cornerstone of the B&O, laid July 4, 1828 by Charles Carroll of Carrollton, now displayed at the B&O 
Railroad MuseumConstruction began on July 4, 1828, when Charles Carroll of Carrollton did the groundbreaking, and the first section, from Baltimore west to Ellicott’s Mills (now known as Ellicott City), opened on May 24, 1830. It was decided to follow the Patapsco River to a point near Parr’s Ridge (now known as Mount Airy) where the railroad would cross a height of land and descend into the valley of the Monocacy and Potomac rivers. Further extensions opened to Frederick (including the short Frederick Branch) December 1, 1831, Point of Rocks April 2, 1832, Sandy Hook December 1, 1834 (the connection to the Winchester and Potomac Railroad at Harpers Ferry opening in 1837), Martinsburg May 1842, Hancock June 1842, Cumberland November 5, 1842, Piedmont July 21, 1851, Fairmont June 22, 1852, and its terminus at Wheeling, West Virginia (then part of Virginia) on January 1, 1853. The narrow strip of available land along the Potomac River from Point of Rocks to Harpers Ferry caused a legal battle between the B&O and the Chesapeake and Ohio (C&O) Canal as both sought to exclude the other from its use.A later compromise allowed the two companies to share the right of way.
The state of Maryland granted the B&O a charter to build a line from Baltimore to Washington, D.C., in 1831, and the Washington Branch was opened in 1835. This line joined to the original mainline at Relay, Maryland, crossing the Patapsco on the Thomas Viaduct, which remains one of the B&O’s signature structures. This line was partially funded by the state, and was operated separately until the 1870s, with the state taking a 25% cut of gross passenger receipts. This line was built in stone, much like the original mainline; by this time, however, strap rail was no longer used for new construction. Most of the stone bridges on the Old Main Line did not last long, being washed out by the periodic flooding of the Patapsco River and replaced at first by Bollman Truss bridges. The Annapolis and Elk Ridge Railroad to Annapolis connected to this line at Annapolis Junction in 1840. As an unwritten condition for the charter, it was understood that the state would not charter any competing line between Baltimore and Washington.
This railroad tin sign is a must for any railroad collector’s collection.