The canal was primarily constructed to gain access to the rich coalfields in the Allegheny Mountains and to provide a reliable route of transportation to a coastal port and thereon to national and international markets. As the canal construction pierced the uneven terrain and the river's course became increasingly tortuous, work became commensurately difficult. The canal's terminus coincided with a small town near the Cumberland Narrows that in turn was the terminus of several small railroads that linked the mines and mining towns scattered across the coalfield's rugged terrain.
For much of this final western stretch, the route of the Baltimore and Ohio (B&O) Railroad loosely parallels the canal's path. Competition was fierce between the canal and the railroad, which ended in Baltimore and challenged Washington's fledgling entrance into the coal trade. Despite claims of the canal's obsolescence after the arrival of the railroad, however, coal continued to be transported via canal to Washington, albeit not very profitably, until well into the twentieth century.