The Baltimore and Ohio Railroad (B&O) was the first common carrier railroad in the United States, established in 1827 to connect the port of Baltimore with the Ohio River. It played a crucial role in the development of transportation infrastructure, significantly impacting trade and commerce by linking the East Coast with the Midwest. The B&O was instrumental in the economic growth of the Appalachian region, facilitating the movement of goods and resources through the rugged terrain of the Ridge-and-Valley system.