The Patowmack Canal

George Washington's life goal was to see the Potomac River navigable as far as the Ohio River Valley. Like many others during his time, Washington knew that transportation and trade were key to economic growth in this new country. He wanted as much as anyone to see a trade-heavy canal system uniting states' economies.

After the Revolutionary War, Washington feared more than ever the loose allegiances of the now sovereign states. There was also still a great desire to continue acquiring land, and finding a pathway to the western frontier. The Ohio River valley west of Pennsylvania's Allegheny Mountains was the goal. The Potomack Canal was one of the Founder's first attempts at an United States; to "...bind those people to us by a chain which never can be broken."

"The way," Washington wrote, "is easy and dictated by our clearest interest. It is to open a wide door, and make a smooth way for the produce of that Country to pass to our Markets..."

As a waterway west, the Potomac River could be that "door." It was the shortest route between tidewater regions of Maryland. It also had access to East Coast and transatlantic trade via Baltimore. Most important, it led to the headwaters of the Ohio River, with access to the western frontier. In the end, political, physical, and financial obstacles had to be overcome to complete the Patowmack Canal.

Patowmack Company Logo
The Patowmack Company Logo. This was one of the first publicly traded companies in the new nation. Shares were being bought and sold in a way that had realtime effects on the companies operation.

NPS Image

The Patowmack Company

The Potomac River is the border between Virginia and Maryland, but the river belongs to Maryland. This geographic challenge altered the course of American history. Opening the Potomac for navigation required cooperation of Virginia and Maryland. Under the Articles of Confederation each state was sovereign. This arrangement meant states couldn't make dealings without consent of the entire Continental Congress.

In 1784, Washington helped lobby the states' assemblies to establish a company to improve navigation on the Potomac. They approved construction of a canal from the Potomac headwaters, to Georgetown. The Patowmack Canal Company incorporated May 17, 1785 and had directors and subscribers from both states.

"The office of president", Washington wrote in his diary, "fell upon me." He presided over the project until he became the nation's first chief executive.

Mount Vernon Conference to Constitutional Convention

Today, the Potomac River still belongs to Maryland. Yet both Maryland and Virginia use the river for commerce, transportation, and recreation. In the spring of 1785, George Washington invited state representatives from Virginia and Maryland to meet at his plantation, Mount Vernon. They discussed developing a beneficial agreement to improve navigation on the Potomac River. The Mount Vernon Compact was later ratified by both state assemblies. This was the first free-trade agreement between states.

In 1786, the remaining 13 states were invited to send delegates to a convention in Annapolis Maryland. They were asked to "to consider how far a uniform system in their commercial regulations may be necessary to their common interest." This was a new concept for post revolution America.

At the time most of the states could not agree on proprietary issues that concerned such challenges as shared waterways. Each state wanted to assert its sovereignty. The Annapolis Convention led to a larger general meeting in Philadelphia the following May, the Constitutional Convention of 1787.

Here is an image a Mason Mark on a large red Seneca Sandstone brick at Lock 02
Stone Masons left marks on the blocks they cut as a way to keep track of their pay. Visitors can find variations of these marks on Seneca Sandstone blocks used to construct Locks 1 and 2. Upstream, the shiny Mica Schits blocks do not have these marks.

NPS Photo: A.Toure

Construction of the Canal

The Patowmack Canal was the first evolutionary stage of America's transportation industry. Construction began on the five part skirting canal system in 1785. After 17 years, the canal was operational in 1802; one year after the locks at Great Falls were complete.

The upriver portions of the canal system were made first. These structures were built with mixed workforces: unskilled laborers, indentured servants, and some enslaved laborers. In 1792, one year after work began at Little Falls, there were over 100 men digging the canal bypass; among them still only 10 listed as enslaved labors. On November 05, 1792 , the Patowmack Company board met to discuss the renting up to 200 enslaved laborers at a cost of $60 a year each. By January 1794 they had only been able to rent 60 enslaved laborers for the coming year. However, it is important to understand that the majority of the ruins you see around you at Great Falls Park today were mostly constructed by enslaved laborers.

The Patwomack Company's constant financial challenges caused a slowdown of construction. When construction began at Great Falls and Little Falls, the labor problems got worse. Indentured servants would run away, and blend into local communities. This situation would default their indenture-mortgages and compound the company's losses. This issue was the main reason company managers continued renting enslaved laborers. Local agricultural operations would often rent their enslaved field hands to the canal. The proximity of slave markets in Alexandria, Georgetown, and Baltimore heightened the demand for enslaved labor to build the infrastructure growing around the capital city.

After 26 years of operation, the Patowmack Company finally succumbed to bankruptcy. The then new Chesapeake & Ohio Canal (C&O) Company acquired the Patowmack Company's charter. The charter and knowledge of the Patwomack Canal's challenges allowed the C&O to build an improved still water canal system in Maryland.
Here is an image of the canal cut. Where boats re-entered the Potomac River on their way to Little Falls Canal.
This is where canal boats would re-enter the Potomac River on their way to Little Falls Canal; before reaching Georgetown's port. Canal Locks 3, 4, and 5 are visible here. Visitors can help preserve this area by viewing Canal Cut from trail overlooks.

NPS Photo: A. Toure

Getting around the Great Falls

The Patwomack Canal's skirting bypasses were made to navigate around five areas of rapids. House Falls, Shenandoah Falls, Seneca Falls, Great Falls, and Little Falls were impassable. Upstream of Great Falls, locks weren't needed. Instead, the river was dredged and boulders moved to accommodate passage. Downstream at Great and Little Falls, canal locks were used to counter elevation changes from the Potomac Gorge to Georgetown.

The canal at Great Falls, in particular, was the most robust of the company’s construction projects. Visitors can still walk along the ruins of the locks on Canal Trail and River Trail. The Canal Cut feature, Locks 2-5— where boats reentered the river—was constructed by blasting through 60 feet of solid rock. Here at Great Falls, black powder was used for the first time in the United States for construction instead of war.

Here is an image of a diagram showing how canal boats were lowered with the locks.
Image of Diagram "How a Lock Works." Location can be found at the entrance to lock 2 on the River Trail in Great Falls Park VA. The boat in this image would not have been used here, but on the larger C&O Canal that came later.

NPS Photo: A. Toure

Transportation on the River

Thousands of boats passed through the Great Falls canal. Farmers carried raw goods such as: flour, whiskey, tobacco, and iron to sell in Georgetown markets. With their profits, they could choose to buy manufactured goods. Items like cloth, hardware, firearms, and other products made their way back to rural places upstream.

Vessels varied from simple rafts to the long narrow "sharper," a keel boat that could carry up to 20 tons of cargo. The trip took 3 to 5 days down to Georgetown and 10 to 12 days poling against the current back to Cumberland.

A National Park

In 1930 Congress authorized preserving the 800 acres around the historic Patowmack Canal as a park. This place of human history and natural beauty transferred to The National Park Service in 1966.

Today, Great Falls Park is a unit of the George Washington Memorial Parkway. The preservation of the Patowmack Canal is part of the National Park Service's continuing efforts to protect and preserve special resources with national significance. The Archeological Resources Protection Act of 1979 protects the Patowmack Canal, Matildaville ruins, and any historic artifacts within Great Falls Park. This law prohibits excavation, removal, or displacement of any archaeological resources.


Last updated: January 24, 2024

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