Chesapeake and Ohio Canal: Washington's Historic Towpath

The Chesapeake and Ohio Canal, commonly called the C&O Canal, is a 296-kilometer (184.5-mile) waterway that runs from Georgetown in Washington, D.C., to Cumberland in western Maryland, following the north bank of the Potomac River through the Appalachian foothills. Built between 1828 and 1850, it was meant to link the Chesapeake Bay to the Ohio River, but it never reached past Cumberland. Today it survives as a national historical park whose towpath is one of the finest long-distance hiking and cycling trails in the eastern United States.

A Canal That Found a Second Life

Few engineering projects in American history failed at their stated mission yet succeeded so completely at a purpose nobody planned. The C&O Canal was designed to carry freight from the Atlantic seaboard deep into the continental interior, competing with railroads for the trade of the trans-Appalachian frontier. It lost that race almost before it began. Yet more than 150 years after the first shovel of earth was turned, the canal draws roughly five million visitors a year as the Chesapeake and Ohio Canal National Historical Park, a 296-kilometer ribbon of preserved towpath, locks, lockhouses, and aqueducts threaded along the Potomac.

The towpath passes through dramatic river gorges, Civil War battlefields, and some of the most beautiful landscape in the mid-Atlantic region of the United States. Walking or cycling its length is, in effect, a continuous tour of nineteenth-century engineering and American history.

History and Construction

The C&O Canal grew out of a vision held by George Washington himself, who as early as the 1780s promoted a Potomac waterway connecting tidewater Virginia and Maryland to the Ohio Valley. His earlier Patowmack Company struggled against the river's rapids, and the C&O was the more ambitious successor: a still-water canal running parallel to the river rather than within it.

Construction began on July 4, 1828, in a ceremony attended by President John Quincy Adams. By a quirk of history, that very same day, in Baltimore, ground was broken for the Baltimore and Ohio Railroad. The two projects were aimed at the same prize — the commerce of the West — and they would race each other up the Potomac valley for the next two decades. The railroad, faster to build and cheaper to operate, won decisively.

The canal's progress was slow and costly. Labor shortages forced the company to recruit immigrant workers, mainly from Ireland; cholera and other epidemics swept the construction camps; financial panics repeatedly drained the company's funds; and floods on the Potomac washed out completed sections. The canal finally reached Cumberland in 1850 after 22 years of work. By then the B&O Railroad had already arrived in Cumberland in 1842, eight years earlier, and the dream of pushing the canal over the Alleghenies to the Ohio River was quietly abandoned.

Geographic Setting

The canal traces the north bank of the Potomac River through a remarkable cross-section of mid-Atlantic geography. From the tidal flats of Georgetown it climbs through the rolling Piedmont, passes the water gap where the river breaks through the Blue Ridge at Harpers Ferry, crosses the limestone floor of the Great Valley near Shepherdstown and Williamsport, and finally enters the ridges of the Allegheny Mountains at Cumberland.

Two natural spectacles stand out. Great Falls, a short distance upstream from Washington, is a series of cataracts where the Potomac drops about 23 meters over jagged rock — one of the most dramatic natural features near any national capital. Farther west, the Paw Paw Bends force the river into a tight ten-kilometer loop around a mountain ridge that canal engineers chose to tunnel straight through.

• Length: 296 km (184.5 miles)
• Route: Georgetown, Washington, D.C., to Cumberland, Maryland
• Follows: The north bank of the Potomac River
• Total rise: About 184 meters from Georgetown to Cumberland

How the Canal Worked

The C&O was a "still-water" or slackwater canal, meaning boats floated on a level channel fed by the river rather than on the river itself. To climb 184 meters from Georgetown to Cumberland, the canal used 74 lift locks, each a chamber whose water level could be raised or lowered to move a boat between two elevations.

Cargo boats were long, narrow wooden barges pulled by mules that walked along the towpath beside the channel. A typical loaded boat carried about 110 tons, most often coal hauled from the mines of western Maryland down to Georgetown for sale and shipment. Boat families frequently lived aboard, with children helping to drive the mule teams.

The canal's engineering highlights included:

• 74 lift locks raising boats the full 184 meters to Cumberland.
• The Paw Paw Tunnel, a 917-meter brick-lined bore through a mountain ridge that took roughly 14 years to complete and was one of the most difficult parts of the whole project.
• Eleven stone aqueducts carrying the canal over tributaries of the Potomac.
• The Monocacy Aqueduct, a seven-arch structure about 170 meters long, widely regarded as one of the finest canal aqueducts in the United States.

Despite this impressive infrastructure, the canal never generated enough revenue to cover its enormous construction debt. Floods repeatedly closed it for costly repairs, and after a devastating flood in 1924 commercial operations ceased for good.

The Civil War on the Canal

Running for much of its length along the border between North and South, the C&O Canal was strategically important during the American Civil War. Both Union and Confederate forces used the waterway and the parallel B&O Railroad, and both sides attacked them to disrupt the enemy's supplies. Confederate raiders breached aqueducts, burned boats, and damaged locks; Union troops guarded crossings and repaired the line.

The towpath runs past or near several major sites of the conflict. It passes close to Antietam, scene of the bloodiest single day in American history in September 1862, and through Harpers Ferry, where abolitionist John Brown launched his famous raid on the federal arsenal in 1859. Walking the towpath today, visitors move through landscape that shaped some of the most consequential events in the nation's past.

The Towpath Today

When commercial use ended, the canal corridor was nearly lost to a proposed highway. In 1954 Supreme Court Justice William O. Douglas, an avid hiker and conservationist, walked the entire 296-kilometer towpath to dramatize the case for preservation, inviting newspaper editors to join him. The campaign succeeded, and in 1971 Congress established the Chesapeake and Ohio Canal National Historical Park.

The towpath is now one of the most popular long-distance trails in the country. At Cumberland it connects directly to the Great Allegheny Passage, a 241-kilometer rail-trail running to Pittsburgh. Together the two form a continuous car-free route of roughly 537 kilometers from Washington, D.C., to Pittsburgh — one of the longest multi-use trails in the United States. Hiking, cycling, camping at riverside hiker-biker sites, kayaking, fishing, and bird-watching are all popular along the corridor, and historic lockhouses can even be rented for overnight stays.

Key Facts

• Location: Maryland and Washington, D.C., along the Potomac River
• Length: 296 km (184.5 miles)
• Built: 1828 to 1850
• Locks: 74 lift locks; total rise of 184 meters
• Longest tunnel: Paw Paw Tunnel, 917 meters
• Park status: National Historical Park since 1971
• Visitors: Approximately 5 million per year

Frequently Asked Questions

Why did the Chesapeake and Ohio Canal never reach the Ohio River?

The canal was always meant to cross the Appalachians and link the Chesapeake Bay to the Ohio River, but construction was far slower and more expensive than planned. By the time it reached Cumberland in 1850, the competing Baltimore and Ohio Railroad had already arrived there eight years earlier and could move freight faster and more cheaply. With no realistic chance of profit, the company never built the western extension over the mountains.

Can you hike or bike the entire C&O Canal towpath?

Yes. The towpath is a continuous 296-kilometer trail from Georgetown in Washington, D.C., to Cumberland, Maryland, open to walkers and cyclists. It is mostly flat and unpaved, with frequent hiker-biker campsites. At Cumberland it joins the Great Allegheny Passage, allowing a through-trip of about 537 kilometers all the way to Pittsburgh.

What is the Paw Paw Tunnel?

The Paw Paw Tunnel is a 917-meter, brick-lined tunnel that carries the canal straight through a mountain ridge, bypassing a tight ten-kilometer loop in the Potomac River. It took about 14 years to build and was one of the most ambitious engineering features of the entire canal. Visitors can still walk through it today, usually with a flashlight, as it is dark inside.

Is the C&O Canal still used for boats?

Commercial boat traffic ended after a major flood in 1924, and the canal is no longer a working freight route. Most of the channel is now dry or holds only shallow water, though some watered sections near Georgetown and Great Falls offer mule-drawn demonstration boat rides. The corridor's main purpose today is recreation and historical preservation.