Monongahela River in the context of "Allegheny Plateau"

In geography, a confluence (also conflux) occurs where two or more watercourses join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main stem); or where two streams meet to become the source of a river of a new name (such as the confluence of the Monongahela and Allegheny rivers, forming the Ohio River); or where two separated channels of a river (forming a river island) rejoin downstream from their point of separation.

The Allegheny River (/ˌælɪˈɡeɪni/ AL-ig-AY-nee; Seneca: Ohi:yo'; Unami: Alikehane) is a 325-mile-long (523 km) tributary of the Ohio River that is located in western Pennsylvania and New York in the United States. It runs from its headwaters just below the middle of Pennsylvania's northern border, northwesterly into New York, then in a zigzag southwesterly across the border and through Western Pennsylvania to join the Monongahela River at the Forks of the Ohio at Point State Park in Downtown Pittsburgh, Pennsylvania.

The Allegheny River is, by volume, the main headstream of both the Ohio and Mississippi Rivers. Historically, the Allegheny was considered to be the upper Ohio River by both Native Americans and European settlers.

The Potomac Highlands of West Virginia (/pəˈtoʊmək/ ), or simply the Potomac Highlands, centers on five West Virginian counties (Grant, Hampshire, Hardy, Mineral, and Pendleton) in the upper Potomac River watershed in the western portion of the state's eastern panhandle, bordering Maryland and Virginia. Because of geographical proximity, similar topography and landscapes, and shared culture and history, the Potomac Highlands region is also considered to include Pocahontas, Randolph, and Tucker Counties, even though they are in the Monongahela River or New River watersheds and not the Potomac River watershed.

The Potomac Highlands broadly overlap but are not identical with the four-state Allegheny Highlands or High Alleghenies region, which includes the relatively high and rugged mountains along and near the Allegheny Front from extreme southern Pennsylvania southward across Maryland and West Virginia into adjacent Virginia.

Pittsburgh (/ˈpɪtsbɜːrɡ/ PITS-burg) is a city in Allegheny County, Pennsylvania, United States, and its county seat. Located in southwestern Pennsylvania where the Allegheny and Monongahela Rivers meet to form the Ohio River, it had a population of 302,971 at the 2020 census, making it the second-most populous city in Pennsylvania. The Pittsburgh metropolitan area has over 2.43 million people, making it the largest in the Ohio Valley and Appalachia, the second-largest in Pennsylvania, and the 28th-largest in the U.S. The greater Pittsburgh–Weirton–Steubenville combined statistical area includes parts of Ohio and West Virginia.

Pittsburgh is known as "the Steel City" for its dominant role in the history of the U.S. steel industry. It developed as a vital link of the Atlantic coast and Midwest, as the mineral-rich Allegheny Mountains led to the region being contested by the French and British empires, Virginians, Whiskey Rebels, and Civil War raiders. For part of the 20th century, Pittsburgh was behind only New York City and Chicago in corporate headquarters employment; it had the most U.S. stockholders per capita. Deindustrialization in the late 20th century resulted in massive layoffs among blue-collar workers as steel and other heavy industries declined, coinciding with several Pittsburgh-based corporations moving out of the city. However, the city divested from steel and, since the 1990s, Pittsburgh has focused its energies on the healthcare, education, and technology industries.

Point State Park (locally known as The Point) is a Pennsylvania state park which is located on 36 acres (150,000 m) in Downtown Pittsburgh, Allegheny County, Pennsylvania, US, at the confluence of the Allegheny and Monongahela rivers, forming the Ohio River.

Built on land that was acquired via eminent domain from industrial enterprises during the 1950s, the park opened in August 1974 after construction was completed on its iconic fountain. Pittsburgh settled on the current design after rejecting an alternative plan for a Point Park Civic Center designed by Frank Lloyd Wright.

Downtown Pittsburgh, colloquially referred to as the Golden Triangle, and officially the Central Business District, is the urban downtown center of Pittsburgh, Pennsylvania, United States. It is located at the confluence of the Allegheny River and the Monongahela River whose joining forms the Ohio River. The triangle is bounded by the two rivers.

The area features offices for major corporations such as PNC Bank, U.S. Steel, PPG, Bank of New York Mellon, Heinz, Federated Investors, and Alcoa. It is where the fortunes of such industrial barons as Andrew Carnegie, Henry Clay Frick, Henry J. Heinz, Andrew Mellon and George Westinghouse were made. It contains the site where the French fort, Fort Duquesne, once stood.

The history of Pittsburgh began with centuries of Native American civilization in the modern Pittsburgh region, known as Jaödeogë’ in the Seneca language. Eventually, European explorers encountered the strategic confluence where the Allegheny and Monongahela Rivers meet to form the Ohio, which leads to the Mississippi River. The area became a battleground when France and Great Britain fought for control in the 1750s. When the British were victorious, the French ceded control of territories east of the Mississippi.

Following American independence in 1783, the village around Fort Pitt continued to grow. The region saw the short-lived Whiskey Rebellion, when farmers rebelled against federal taxes on whiskey. The War of 1812 cut off the supply of British goods, stimulating American manufacture. By 1815, Pittsburgh was producing large quantities of iron, brass, tin, and glass products. By the 1840s, Pittsburgh had grown to be one of the largest cities west of the Allegheny Mountains. Production of steel began in 1875. During the 1877 railway riots it was the site of the most violence and damage in any city affected by the nationwide strikes of that summer. Workers protested against cuts in wages, burning down buildings at the railyards, including 100 train engines and more than 1,000 cars. Forty men were killed, most of them strikers. By 1911, Pittsburgh was producing half the nation's steel.

Fort Duquesne (/djuː.ˈkeɪn/ dew-KAYN, French: [dykɛːn]; originally called Fort Du Quesne) was a fort established by the French in 1754, at the confluence of the Allegheny and Monongahela rivers. It was later taken over by the British, and later the Americans, and developed as Pittsburgh in the U.S. state of Pennsylvania. Fort Duquesne was destroyed by the French before its British conquest during the Seven Years' War, known as the French and Indian War on the North American front. The British replaced it, building Fort Pitt between 1759 and 1761. The site of both forts is now occupied by Point State Park, where the outlines of the two forts have been laid in granite slabs.