Chester County was one of the three original counties established by William Penn, giving it a long history of settlement and growth. Around Avondale and West Grove features historic postcards from Avondale, Baker's Station, Chatham, West Grove, and the surrounding area. Jennersville, located in Penn Township, has close ties to the rose industry begun in London Grove. This area was a rich agricultural district that had many nurseries (including one of world renown), creameries, mushroom farms, horse farms, an experimental farm for research, and other agricultural ventures. White Clay Creek, now a federally designated wild and scenic river, supported many mills. Granite and marble supplied the quarry industry. The township's location along the main highways between Lancaster, Wilmington, Philadelphia, and Baltimore made it an important route for commerce.