Green Park developed as an early industrial center because abundant clay and sand supported brickmaking, Montour Creek provided reliable water power, and local residents pursued enterprise. In 1806, farmer John Henry Bernheisel built the large brick house north of this site, and when he died in 1825 at age 60, he left his family 330 acres, the house, and a sawmill. In 1832, his son Jacob sold the mill, mill race, tail race, and 15 acres along the waterway to his brother Solomon, who by 1835 had built the large brick mill nearby, originally for processing hulled clover seed, along with a separate fulling mill and carding mill. The Bernheisel family showed a strong inventive spirit: Jacob operated a machine shop and received a patent in 1867 for a corn sheller, separator, and feeder; his son George was a machinist and grain cradle maker; and by 1860 Peter owned an iron foundry known as P. Bernheisel & Company just west of the Green Park School. In the late 1870s, John T. and David Rheem, operating as Rheem & Brothers, bought the foundry, which made the bell for the Green Park school, and Peter returned to farming. Green Park, midway in Perry County between Conococheague Mountain and the Susquehanna River, became central to the county’s early industrial development, and later features included a flour bolt patented in 1876 by Solomon Bernheisel and Joseph Young and a railroad trestle that from 1893 to 1903 carried the Perry County Railroad over the Newport and Sherman's Valley Railroad west of Montour Creek.