Allegheny

Formed September 24, 1788 (19th county)

Allegheny County (1,250,585), Pittsburgh (302,958)

A brown stone facility is the 1888 Richardsonian Romanesque courthouse in Pittsburgh.  The courthouse is on Grant Street between 4th and Forbes avenues.  Henry Hobson Richardson is the building designer.  United States Highway 30 is four blocks south of the location.  There is a 1917 Administrative Building that supports the courthouse.  The county was created on September 24, 1788 from parts of Washington and Westmoreland counties as the 19th county with Pittsburgh as the only county seat.  Allegheny County is named for the Allegheny River.  The county seat is named for British Secretary of State William Pitt the Elder.  Allegheny County is the birthplace of 4 Pennsylvania governors, James H. Duff, David L. Lawrence, Richard L. Thornburgh, and Thomas J. Ridge. 

Allegheny County government consists of a treasurer, a sheriff, an attorney, a coroner, and a clerk (executive).  It has 13 Council Members (legislative.)  Fifty-four Common Pleas Court Judges and Forty-six Magistrate Court Judges serve Allegheny County (judicial.)  The county is in western Pennsylvania.  The Ohio River forms in the county and flows northwest.  Erie, Pennsylvania is north and Harrisburg, Pennsylvania is east of the county.  The county center is in Pittsburgh 1 mile Northwest of the city center.  The county is surrounded clockwise by Butler, Westmoreland, Washington, and Beaver counties. 

The area of the county is 745 square miles.  It is 30 out of 67 in the state.  It ranks 2 out of 67 in population in the state.  It has a density of 1678.6 persons per square mile making it 4 out of 67 in the state.  Allegheny County has 61.2% of its population in its incorporated areas.  Interstate Highway 76 travels through the county from northwest to southeast from Butler County to Westmoreland County.  Interstate Highway 79 goes north to south from Butler County to Washington County.  United States Highway 19 parallels Interstate Highway 79 from Butler to Washington counties.  United States Highway 22 enters from Westmoreland County, east, and exits to Washington County, west.  United States Highway 30 comes from Westmoreland County and goes east to Beaver County.  The county looks like the head of a hatchet.  Pittsburgh dominates the center of the county.  Pittsburgh is the county seat and the largest city.  It is 24.2% of the county population.  The county is pronounced AL-LE-GAE-NEE.  This county is in the Pittsburgh Metropolitan Statistical Area.

Location in State and Municipalities

Aspinwall

Avalon

Baldwin

Bell Acres

Bellevue

Ben Avon

Ben Avon Heights

Bethel Park

Blawnox

Brackenridge

Braddock

Braddock Hills

Bradfordwoods

Brentwood

Bridgeville

Carnegie

Castle Shannon

Chalfant

Cheswick

Churchill

Clairton

Coraopolis

Crafton

Dormont

Dravosburg

Duquesne

East McKeesport

East Pittsburgh

Edgewood

Edgeworth

Elizabeth

Emsworth

Etna

Forest Hills

Fox Chapel

Franklin Park

Glassport

Glenfield

Glen Osborne

Green Tree

Haysville

Heidelberg

Homestead

Ingram

Jefferson Hills

Leetsdale

Liberty

Lincoln

McKeesport

McKees Rocks

Millvale

Mount Oliver

Munhall

Monroeville

North Braddock

Oakdale

Oakmont

Pennsbury Village

Pitcairn

Pittsburgh

Pleasant Hills

Plum

Port Vue

Rankin

Rosslyn Farms

Sewickley

Sewickley Heights

Sewickley Hills

Sharpsburg

Springdale

Swissvale

Tarentum

Thornburg

Turtle Creek

Verona

Versailles

Wall

West Elizabeth

West Homestead

West Mifflin

West View

Whitaker

Whitehall

White Oak

Wilkinsburg

Wilmerding

McDonald

Trafford

Jerry Fager
Courthouses.co
Administration Building (Courthouses.co)