West Mifflin is located southeast of downtown Pittsburgh. It was once part of larger Mifflin Township. As the area incorporated into many other townships, West Elizabeth, Jefferson, Baldwin and others, West Mifflin was actually changed from a township into a borough in 1944, the first time it was done in this manner. The borough is about 14 square miles, and includes Kennywood Park, founded in 1898 and perhaps the oldest amusement park in the United States.
It was also home to “Browns Dump”, where slag, a by-product of steel production, was dumped 24 hours a day from the early 1900s until the 1960s. In the late 1970s this “mountain” became the site of Century III Mall, then the 3rd largest mall of it’s kind in the world. Century III has since closed.
The name “Mifflin” was taken from Thomas Mifflin, the first elected governor of Pennsylvania, serving from 1790 to 1799. He died in 1800.
West Mifflin has ten land borders, including the Pittsburgh neighborhoods of Lincoln Place and Hays as well as Munhall and Whitaker, to the north, Duquesne to the east, Dravosburg to the southeast, Jefferson Hills and Pleasant Hills to the south, Baldwin to the west and also a short border with Clairton to the south.
Three segments of West Mifflin run along the Monongahela River. Adjacent to these areas across the river are Braddock, North Braddock, McKeesport and Glassport.