On July 4, 1828, Charles Carroll of Carrollton, the last surviving signer of the Declaration of Independence, broke ground for the cornerstone of the Baltimore & Ohio Railroad. Many notables from Maryland, Virginia and Pennsylvania, including Philip E. Thomas, the first President of the railroad, witnessed this memorable occasion. This historic event took place on the farm of a relative of Carroll's, James Carroll, on Gwynn's Run, now the west end of Mount Clare shop near Monroe Street. From the beginning there was constant expansion of this great railroad.

In 1882, Mr. Acton and other citizens of Brooklyn, requested that a branch line of the B & O be extended to the Brooklyn-Curtis Bay peninsula. This was a fortunate move for both the railroad and Masonville, Fairfield, Wagner's Point and Curtis Bay. Switches and sidings were put into many factories and commerce expanded in the entire area.

Soon after the Baltimore & Ohio came into Brooklyn, with its extension into Curtis Bay, there was an early morning train which left Camden Station to bring workmen to this area, returning them to the city in the afternoon. It also honored other passengers who with the purchase of a five cent ticket could use this method of conveyance. Old timers tell how school teachers, too, came from Baltimore on the B & O until the coming of the trolley in 1893. Mrs. David Steele Clarke of Curtis Bay has in her possession a ticket marked "one fare from Camden Station to Filbert Street".

The prime mover in further extending the branch was Curtis Bay in particular, for there were soon thousands of tons of freight ready for the rail, and with such a deep, natural harbor, it became an export terminal of first magnitude. In later years, after the most modern coal pier was completed, a record was made in the mid 1920's during the Great Britain coal strike. The Curtis Bay Coal Pier broke the world's record in dumping 1,000 cars of coal into the hatches of the British coal colliers in twenty-four hours. Curtis Bay had now grown to be the largest and most important terminal in the port of Baltimore.