With construction of the Erie Canal and the National Road, the citizens of Philadelphia became worried of the loss of trade to New York City and Baltimore, Maryland, and persuaded the state government to invest in a transportation network to travel west over the Allegheny Mountains.
The building of the Erie Canal and National Road caused concern among Philadelphians regarding potential trade shifts away from their city towards New York City and Baltimore. This led them to advocate for the state government to fund a westward transportation system across the Allegheny Mountains.