The Delaware Estuary has sustained a human population for thousands of years, but by the end of the 19th Century, increased population and industrialization had transformed much of the upper Estuary watershed.

2012

Gerlach was again challenged by Democratic nominee Manan Trivedi. In all three contests Gerlach survived by swamping his Democratic opponents in Chester County where he resides. He defeated Democrat Barry Robertson (whose campaign was heavily funded by Sam Morris Gerlach's opponent four years earlier) in that election and was re-elected in 1998 without opposition.

Representative for Pennsylvania's 6th congressional district serving since 2003. James "Jim" Gerlach (born February 25 1955) is the U.