that the canal would be clogged by floods or frozen up for half
of each year, and that commerce would ignore artificial courses
and cling to natural channels. But the answer of the Empire State
to her rivals was the homely but triumphant cry "Low Bridge!"--
the warning to passengers on the decks of canal boats as they
approached the numerous bridges which spanned the route. When
this cry passed into a byword it afforded positive proof that the
Erie Canal traffic was firmly established. The words rang in the
counting-houses of Philadelphia and out and along the Lancaster
and the Philadelphia-Pittsburgh turnpikes--"Low Bridge! Low
Bridge!" Pennsylvania had granted, it has been pointed out, that
her Southern neighbors might have their share of the Ohio Valley
trade but maintained that the splendid commerce of the Great
Lakes was her own peculiar heritage. Men of Baltimore who had
dominated the energetic policy of stone-road building in their
State heard this alarming challenge from the North. The echo ran
"Low Bridge!" in the poor decaying locks of the Potomac Company
where, according to the committee once appointed to examine that
enterprise, flood-tides "gave the only navigation that was
enjoyed." Were their efforts to keep the Chesapeake metropolis in
the lead to be set at naught?

There could be but one answer to the challenge, and that was to
rival canal with canal. These more southerly States, confronted
by the towering ranges of the Alleghanies to the westward, showed
a courage which was superb, although, as time proved in the case
of Maryland, they might well have taken more counsel of their
fears. Pennsylvania acted swiftly. Though its western waterway--
the roaring Juniata, which entered the Susquehanna near
Harrisburg--had a drop from head to mouth greater than that of