Beginning in 1849, Mifflin (then called Patterson) was the booming center of the Pennsylvania Railroad's repair shops until 1869 when the work was transferred to Altoona. A tightly packed town of clapboard and brick buildings sprang up around the shops. In 1910, the town was renamed Mifflin, linking it to the county seat across the river. William Cookman, the in-house architect for the Pennsylvania Railroad from shortly after his graduation from the University of Pennsylvania in 1887 until at least 1936, is the station's likely designer. A simplified version of Price and McLanahan's modern Steubenville, Ohio, station with a raised central parapet above the principal entrance, Mifflin station is now used as an office by Norfolk Southern, who owns the railway.