Allegheny County, Pennsylvania
Allegheny County | |
|---|---|
Location within the U.S. state of Pennsylvania | |
Pennsylvania's location within the U.S. | |
| Coordinates: 40°26′08″N 80°01′28″W / 40.4356°N 80.0244°W | |
| Country | United States |
| State | Pennsylvania |
| Founded | September 24, 1788 |
| Named after | Allegheny River |
| Seat | Pittsburgh |
| Largest city | Pittsburgh |
| Area | |
• Total | 745 sq mi (1,930 km2) |
| • Land | 730 sq mi (1,900 km2) |
| • Water | 14 sq mi (40 km2) 1.9% |
| Population (2020) | |
• Total | 1,250,578 |
• Estimate (2023) | 1,224,825 |
| • Density | 1,700/sq mi (700/km2) |
| Time zone | UTC−5 (Eastern) |
| • Summer (DST) | UTC−4 (EDT) |
| Congressional districts | 12th, 17th |
| Website | alleghenycounty.us |
| Designated | December 30, 1982 |
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Allegheny County (/ˌælɪˈɡeɪni/ AL-ig-AY-nee) is a county in Pennsylvania, United States. As of the 2020 census, the population was 1,250,578, making it the state's second-most populous county, after Philadelphia County. Its county seat and most populous city is Pittsburgh, Pennsylvania's second most populous city. The county is part of the Greater Pittsburgh region of the commonwealth, and is the center of the Pittsburgh media market.
Allegheny was the first county in Pennsylvania to be given a Native American name. It was named after the Lenape word for the Allegheny River. The meaning of "Allegheny" is uncertain. It is usually said to mean "fine river". Some historians state that the name may come from a Lenape account of an ancient mythical tribe called "Allegewi", who lived along the river before being taken over by the Lenape.