St. Clair Township,

Allegheny County, Pennsylvania Allegheny County ( ) is a County (United States), county in Pennsylvania, United States. As of the 2020 census, the population was 1,250,578, making it the List of counties in Pennsylvania, state's second-most populous county, after Philadelp ...

, was one of the original townships created with the incorporation of Allegheny

County A county () is a geographic region of a country used for administrative or other purposesL. Brookes (ed.) '' Chambers Dictionary''. Edinburgh: Chambers Harrap Publishers Ltd, 2005. in some nations. The term is derived from the Old French denoti ...

in 1788. The township was named after

Arthur St. Clair Major-General Arthur St. Clair ( – August 31, 1818) was a Scottish-born American military officer and politician. Born in Thurso, Caithness, he served in the British Army during the French and Indian War before settling in the Province of Pe ...

, an

American Revolutionary War The American Revolutionary War (April 19, 1775 – September 3, 1783), also known as the Revolutionary War or American War of Independence, was the armed conflict that comprised the final eight years of the broader American Revolution, in which Am ...

general A general officer is an Officer (armed forces), officer of high rank in the army, armies, and in some nations' air force, air and space forces, marines or naval infantry. In some usages, the term "general officer" refers to a rank above colone ...

and president of the

Continental Congress The Continental Congress was a series of legislature, legislative bodies, with some executive function, for the Thirteen Colonies of British America, Great Britain in North America, and the newly declared United States before, during, and after ...

in 1787. The township extended from the

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and Monongahela rivers to the southern county line. It was bounded on the west by

Chartiers Creek Chartiers Creek is a tributary of the Ohio River in Western Pennsylvania in the United States. The creek was named after Peter Chartier, a trapper of French and Native American parentage who established a trading post at the mouth of the cr ...

and on the east partially by

Streets Run Streets Run is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed August 15, 2011 tributary of the Monongahela River in Allegheny County, Pennsylvania. This urban stream drains portion ...

. The township was subsequently divided between the northern part, Lower St. Clair Township, and the southern part, Upper St. Clair Township. The "upper" and "lower" referred to the

elevation The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...

, as Lower St. Clair bordered on the

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

, the lowest elevation, and Upper St. Clair extended into the South Hills of Pittsburgh. The original Lower St. Clair Township consisted of the present-day neighborhoods of the City of Pittsburgh south of the Monongahela and Ohio, and all or parts of Green Tree, Carnegie, Baldwin, Bridgeville, Dormont, Mount Lebanon and other boroughs and townships in the South Hills. The township was subdivided several times, and today exists only as the neighborhood of St. Clair in the City of Pittsburgh. Upper St. Clair Township, subdivided many times, still exists in the South Hills of Pittsburgh.

References

{{Pittsburgh, Allegheny County, Pennsylvania Former townships in Allegheny County, Pennsylvania