Mill Creek took its name from the active mill industry that flourished there from the 1790s to the 1870s, adapting to changing markets as mills in the early 1800s produced paper, grain, guns, and powder before cotton yarn became the predominant product in the 1850s. The industry declined during the 1890s, when large automated factories along railroad lines outcompeted the smaller mills, and after a disastrous flood in 1893 destroyed the dams along the creek, they were never rebuilt. The existing industrial buildings along Mill Creek adjacent to the park boundaries are known as the Barker Mill, the longest-lived mill on the creek, on land that was part of William Penn’s 1682 patent to Robert Jones for the Welsh Barony. Benjamin Brooke is believed to have built the first mill there around 1794, either to produce powder or manufacture armaments, and from 1808 to 1861 the Nippes family operated a mill manufacturing rifles, including supplying rifles to the United States Government during the War of 1812. In 1881 the mill was sold to William Booth, and the cornerstone on the existing building reads “Wm Booth Roseglen Mill 1886”; it produced carpet and rug yarn. Its later name came from Thomas A. Barker, who bought the mill in 1923, and he and his sons carded and spun wool there until the 1950s, before the building was renovated in the 1970s for light industrial, office, and artisan studio uses. Along the floodplain of Mill Creek, large stone ruins once housed mill workers, while the mills themselves generally employed about 6-10 workers; the 1850 census showed a population dominated by laborers, mill workers, and local craftsmen, and workers lived in property tenements that could accommodate several families. Two major sets of ruins remain along the floodplain: a three-story stone mill workers’ tenement built between 1837 and 1840 by mill owner Samuel Lehman Smith, with a nearby root cellar, and downstream closer to the Barker Mill, two buildings dating from the first quarter of the 19th century, one a single unit for one family or several workers and the other a double unit for two families, both with crafted stonework, heavy fireplace lintels, and attached kitchens.