Port-town humidity, courthouse to waterfront
Mount Vernon incorporated in 1832 and grew from a riverside cabin into the seat of Posey County and a major Ohio River port, with traffic peaking between 1850 and 1870. Port towns accumulate humidity year-round from river proximity, and Mount Vernon's older courthouse-district and waterfront-adjacent buildings have absorbed nearly two centuries of that moisture exposure.
Older port-era buildings and a newer port complex
The modern Ports of Indiana-Mount Vernon complex sits alongside a town core built up over generations, and mold assessment here needs to distinguish between older, more moisture-exposed construction near the original townsite and newer buildings elsewhere in town.