History:

West Mifflin has a population of 20,313( 2010 census) and was named after the first Elected Governor of Pennsylvania, Governor Thomas Mifflin (1744-1800) 1st Governor of Pennsylvania, signer of the United States Constitution, and 1st Quartermaster General of the United States Army. Mifflin Township was one of the seven original townships, when the county was carved out of Washington and Westmoreland Counties on December 16, 1788. Mifflin Township came with the purchase of 1784 from Virginia, while land south of the Monongahela and Youghiogheny rivers was acquired in 1768 from Maryland. Mifflin Township at that time was in Yohogania County Virginia. ere, Washington later engaged in military operations from Fort Necessity at Braddock’s Field (Braddock).

In 1938, the Township Commissioners went to Harrisburg and were influential in getting the passage of Act #333 of the 1941 Session of the General Assembly, engaging Mifflin Township to incorporate as a Borough. It was the first time an entire township became a borough. Mifflin Township ceased to exist as of January 3, 1944 – after 156 years. West Mifflin was incorporated as a borough January 3, 1944.

West Mifflin Borough’s perimeter is somewhat irregular. The shape is elongated, resembling an hourglass with the narrowest portion at the approximate center squeezed between Pittsburgh and Dravosburg. Due to the fact that there is a Mifflin County in central Pennsylvania and a town named Mifflin in Juniata County, the prefix “West” was added to our new Borough.

West Mifflin boundaries began at the mouth of Streets Run (Six Mile Ferry), up the Monongahela River to the line of Washington County and by that said line to the line of Saint Clair Township. Streets Run was at Hays (now the 31st Ward of the City of Pittsburgh). It covered more than twelve miles along the river. Mifflin Township included Hays, West Homestead, Munhall, Whitaker, Duquesne, Dravosburg, Lincoln Place, Jefferson Hills, Pleasant Hills and part of Baldwin. A series of annexations and secessions reduced it to 14.35 square miles.

Although the borough is heavily residential, it is home to one of America's oldest traditional amusement parks, Kennywood Park. Other employers include advanced naval nuclear propulsion technology research and development facility, Bettis Atomic Power Laboratory; monorail manufacturer Bombardier; US Steel's Mon Valley Works–Irvin Plant; Community College of Allegheny County's South Campus; and the Allegheny County Airport.