The Baltimore and Ohio Railroad (B&O) was one of the first railroads in the United States, established in 1827. It played a crucial role in the development of the American transportation system, connecting the eastern cities of Baltimore and Washington, D.C. with the Ohio River Valley. The B&O was instrumental in facilitating trade and the movement of goods across the country. Throughout its history, the B&O expanded its network, reaching as far as Chicago and St. Louis. It became known for its innovative practices, including the use of steam locomotives and the establishment of the first scheduled freight service. The railroad eventually merged with other companies and remains a significant part of American rail history.