Photo: Looking upstream along the Monongahela River from Mount Washington in Pittsburgh, PA. Photographed by User:Matthiasb, 2007, [cc-by-2.5], via Wikimedia Commons, accessed August, 2020.
Historic Resources of the Monongahela River Navigation System in Pennsylvania and West Virginia, 1838-1960 [†] was listed on the National Register of Historic Places in 2010.
The Monongahela River  has its source in the mountains of West Virginia, at the junction of the Tygart Valley and West Fork Rivers south of Fairmont, and flows north into Pennsylvania for 128.7 miles to Pittsburgh, where it joins the Allegheny River to form the Ohio River. From its headwaters, the Monongahela winds its way downhill through rugged terrain and a well-defined valley, draining part of what is known as the Allegheny Plateau, "a wide and choppy sea of considerable local relief' (Wood 1996: 99), until it reaches its mouth at Pittsburgh. The river flows through or touches two West Virginia counties, Monongalia and Marion, and five Pennsylvania counties— Greene, Washington, Fayette.
The Monongahela is about one-third the length of the Allegheny and was long considered by some to be merely a tributary of a combined Ohio-Allegheny River (Kussart 1938:1). The Monongahela, however, has ultimately carried much more traffic through the region as it has tapped the resources of Virginia, West Virginia and southwestern Pennsylvania. It was, in its natural state, a more difficult and dangerous river to navigate and was the subject of improvement efforts early in the area's settlement period.
The Youghiogheny River, the main tributary of the Monongahela, flows into the latter near the present town of McKeesport, and together the two rivers drain the southwestern portion of the state. The headwaters of the Youghiogheny are in the Laurel Highlands of western Pennsylvania. Although the gradient is steep at the upper end, the Youghiogheny River has been navigable generally from about three miles above Connellsville to its end at the Monongahela. The Youghiogheny Valley contained vast deposits of coal and stands of timber and lesser amounts of iron ore and limestone (Gilpin 1975: 37-42).
Americans have always had a passion for movement and mobility. As settlers moved inexorably west, they searched for good, cheap transportation, and, after the Revolutionary War, the leaders of the fledgling nation recognized the importance of connecting its various geographic sections. These two needs converged during the first half of the nineteenth century in what historians have called the Transportation Revolution, the development of a vast system of internal improvements. Despite the fact that individual improvement projects were sometimes haphazardly conceived and constructed, technological change proceeded at a dizzying pace, producing engineering feats that astounded the world. Roads, canals, rivers, and railroads were all subjects of innovative transportation solutions.
Economic incentives also played a significant role in the development of America's nineteenth-century internal improvements network. Emigrants moving west needed the manufactured products of the industrializing East; the settled regions wanted the agricultural commodities of the fertile new territories. To satisfy both migrants and merchants, the United States was forced to address its geographical problems and find negotiable, economically viable routes across the Appalachian Mountains. The Monongahela River, as one part of that solution, served as an important link in the settlement and commercial development of the new nation.
The State of Pennsylvania took an early interest in the Monongahela River, declaring it a public highway in 1782 and beginning navigation improvements ten years later. In its natural state, the Monongahela could be extremely difficult to navigate, as rapids, narrow channels, sand bars, snags, and boulders were common hazards; the current was slow, and much of the year the water level was very low. The first state-funded improvements on the Monongahela River consisted simply of channel clearing and snag removal, but they coincided with the first great wave of emigration into the Ohio country and the old Northwest Territory.
In 1814 and 1815, the Pennsylvania legislature recommended surveys of the Monongahela with an eye to further river improvement and in 1822 appropriated funds for channel-dredging and snag-removal projects. These continuing improvements facilitated navigation from the mouth of the Monongahela at Pittsburgh upriver as far as Morgantown by 1826. Although improvements in Pennsylvania continued to be funded privately or at the state level for many years, Congress authorized and provided funding for surveys and improvement projects on rivers, harbors, and canals generally, beginning in 1824. It was largely the rapid development and subsequent impact of the steamboat on western rivers that led Congress to pass the waterways and improvement legislation.
The chief advantage of steamboats was that they could move back upstream under their own power, carrying a full load of both passengers and cargo. Steamboats were the driving force behind the industrial development of the Monongahela-Allegheny-Ohio-Mississippi Valleys during the forty-five years preceding the Civil War, "the golden age of the river steamboat." Steamboats proved their value early in hauling passengers and freight, and in a development that came to be particularly important on western Pennsylvania rivers, began serving as towboats on the Ohio, Monongahela, and Allegheny, carrying coal and other resources to markets north, south, and west of Pittsburgh.
The Monongahela River Valley entered the boat-building business as early as the eighteenth century when garrisons stationed at Fort Pitt constructed bateaux for use in their military maneuvers on western Pennsylvania rivers. Settlers traveling west along the trails and rough roads of Pennsylvania and Maryland built flatboats and later keelboats when they reached the Monongahela or Youghiogheny in order to carry their families and agricultural products downstream to Pittsburgh and into the Ohio country beyond. Boatyards capable of turning out hundreds of boats each year soon sprang up in communities such as Brownsville. Several other towns in the Monongahela Valley—Elizabeth, Monongahela, Belle Vernon, McKeesport, and California also developed impressive construction operations. By 1830, the Pittsburgh area had no rival as the center of the western steamboat-building industry, a position it held for the next two decades.
In 1836 the state chartered a private corporation, the (second) Monongahela Navigation Company, to construct a slackwater navigation system of locks and dams extending ninety-two miles from Pittsburgh to the [West] Virginia state line. Construction on the first two locks and dams finally got under way in the summer of 1839. The Monongahela system was one of the first in the United States to be designed specifically for steamboats.
The first four locks and dams were in place and opened to river traffic in November of 1844, making it possible to navigate on five feet of slackwater for nearly sixty miles upriver, as far as Brownsville. By 1856 Locks Nos. 5 and 6 had extended slackwater another twenty-five miles. Following the Civil War, mining and business interests in Morgantown and Fairmont, West Virginia, called for extending slackwater navigation on the upper Monongahela River, and in 1871 federal legislation provided funds for surveys of the upper river. Locks and Dams Nos. 8 and 9 were constructed by the Corps of Engineers and No.7 by the MNC between 1879 and 1889 to provide slackwater as far as Morgantown. In 1897 the Corps of Engineers assumed complete control over MNC property, thus creating a single free (no tolls) navigation system between Pittsburgh and Morgantown, West Virginia.
Five general kinds of goods were shipped on the Monongahela River system: agricultural products, extractive resources, manufactured goods, livestock, and eastern merchandise, but the most important of the products, without doubt, was coal. The coal trade provided the fuel for Pittsburgh's furnaces, foundries, and mills that produced munitions and armament during the Civil War. In addition, Monongahela Valley coal powered the boats that the Union used to keep the Mississippi River open for travel and shipping during the war and the railroads that increasingly tied the nation together.
The system transformed the coal industry overnight by providing navigable water at the loading areas near the mines. Shipping costs were slashed, and consumers were ensured a reliable supply of coal that was no longer dependent on river conditions. Furthermore, convenient access to large quantities of extremely cheap coal gave Pittsburgh manufacturers a huge competitive advantage over down-river rivals, who also relied on Monongahela Valley coal, but at inflated prices. It was these great quantities of coal, cheaply and regularly transported, that was at the core of Pittsburgh's early manufacturing development. Every coal barge that passed through a lock represented a toll paid to the MNC, whose revenues increased steadily over this period.
The slackwater system also had a tremendous impact on the boat-building industry in the lower Monongahela Valley. The huge increase in river commerce that occurred after construction of the locks and dams on the lower river led to an intensification of boat-building activity at a host of towns. Hundreds of hulls and completed vessels were constructed at local boatyards for both local and downriver customers, including large vessels destined for the Ohio and Mississippi rivers. By the late 1880s, however, most of the passenger boats being built for the inland river trade had become too large to be sent through Monongahela River locks, and the boat-building industry in the valley declined.
Most of the towns along the Monongahela predated the development of the slackwater navigation system, but, by 1850, the Monongahela Navigation Company's locks and dams both directly and indirectly had increased the population, capital, and land values of the lower part of the valley from Brownsville to Pittsburgh. Town and population growth in the Monongahela Valley was further stimulated by the development of the coal and coke industries. Industrial coal mining in the later nineteenth and early twentieth centuries required the establishment of coal patches and towns near the mines to accommodate workers and their families, and this is the origin of many of the coal towns that dot the banks of the Monongahela River.
By the time that the federal government acquired the Monongahela Navigation System, several of the MNC's older facilities had deteriorated seriously. The small locks were also inadequate to handle the large tows that had become common on the river. Over the twenty years between 1897 and 1917, the Corps of Engineers repaired or replaced most of the facilities on the lower and middle sections of the river. By World War I, all of the locks on the lower river had been rebuilt to new standard dimensions, and after the war, the Corps planned additional changes to the system that they hoped would speed transit time on the river and reduce labor and maintenance costs in lock operations. They began to consolidate and re-engineer some of the facilities in order to create a higher lift and reduce the need for a number of the existing locks and dams.
In 1938 the Emsworth Dam on the Ohio River was replaced, raising the upper Ohio pool which extended into both the Monongahela and Allegheny Rivers, eliminating the need for Locks and Dams No.1 on each. Also in 1938, the Pittsburgh District, as part of a series of flood-control projects, constructed a reservoir on the Tygart River in West Virginia to augment the flow on the upper Monongahela during periods of drought.
Beginning in the 1920s, the major steel companies in the Monongahela Valley began to use the river much more heavily to ship both raw materials and finished steel products, where they had previously relied upon the railroads. Coal and coke also continued to account for a huge percentage of the barge traffic on the river. The Monongahela River throughout the twentieth century has consistently carried more daily commercial traffic than any other river system in the United States and much of the world (U.S. Army Corps of Engineers 1994: 51, 52).
After World War II, the Corps of Engineers initiated its second major improvement program, this time focusing on obsolete navigation facilities on the middle and upper river. Between 1946 and 1996, the Corps closed its repair shops and boatyard at North Charleroi, replaced Locks and Dams Nos. 10-15 in West Virginia, and completed three new locks and dams on the middle river, thus eliminating or replacing four older facilities. In 1992, Congress authorized the Corps' plan to modernize the locks and dams on the lower river (the "Lower Mon Project"), representing the final stage of its post-war modernization and consolidation program. In 2004, Locks and Dam 2 was renamed Braddock Locks and Dam upon the completion of the replacement gated dam. Work is in progress on the first of two new locks at Locks and Dam 4 as of 2010. Once the first lock is operational, the pools maintained by Braddock Dam and Dam 3 will be equalized and Locks and Dam 3 will be removed. The removal of Locks and Dam 3 will result in a system of eight lock and dam facilities in the place of fifteen that once provided slackwater the length of the Monongahela.
1937 Navigation on the Monongahela River. Printed collection of newspaper files, on file at the Pennsylvania Room, Carnegie Library of Pittsburgh and Library of the Historical Society of Western Pennsylvania.
1938 The Allegheny River, Burgum Printing, Pittsburgh, PA
U.S. Army Corps of Engineers (COE), Pittsburgh District
The Monongahela River Navigation System: An Historical Contextual Overview of the Locks and Dams on the Monongahela River Allegheny, Washington, Westmoreland, Greene and Fayette Counties, Pennsylvania, Monongalia and Marion Counties, West Virginia. Draft report.
Walker, Joseph E., Editor
1975 Pleasure and Business in Western Pennsylvania: The Journal of Joshua Gilpin 1809. Pennsylvania Historical and Museum Commission, Harrisburg, PA.
† Adapted from: Judith A. Heberling, Ph.D. and Scott D. Heberling, M.A., Co-Principal Investigators, Heberling Associates, Historic Resources of the Monongahela River Navigation System in Pennsylvania and West Virginia, 1838-1960, nomination document, 2000, National Park Service, National Register of Historic Places, Washington, D.C.