Through the center of Pennsylvania flows the Susquehanna, the longest river in the East if you include the Chesapeake Bay, which is actually the flooded lower Susquehanna Valley. Starting in Cooperstown, N.Y., emptying into the Chesapeake next to the antique town of Havre de Grace, Md., the Susquehanna is the one river strong enough to break through the Appalachian Mountain chains of central Pennsylvania. But few songs are written to celebrate the Susquehanna. It has not been named for a fever (Potomac), for a school of painting (Hudson) or economics (Charles), or for a state (Delaware, Connecticut, Ohio, Mississippi, Alabama, Illinois, Missouri, Colorado, Tennessee). And its dams are silting up and threatening environmental havoc on the tenuously recovering Chesapeake, unless the unwieldy grouping of states through which the Susquehanna runs can find a solution. Already, millions of fish and fish eggs are killed each year by pollution. In 2005, the conservation group American Rivers rated the Susquehanna the nation’s “most endangered river,” due mostly to sewer system discharge. Low river flows in recent droughts resulted in large fish kills.

The 17th Congressional District of Pennsylvania includes two distinct areas: the agricultural lands adjoining the Susquehanna River, and the industrial areas of Schuylkill and Berks counties. Forty percent of the district is centered on the state capital of Harrisburg. It includes Dauphin County, part of Perry County and Lebanon County. Harrisburg features a string of mansions-turned-lobbying headquarters gracefully lining the banks of the Susquehanna and boasts Pennsylvania’s marvelously restored Capitol building—its dome is modeled after St. Peter’s in Rome, its stairway on the Paris Opera. Nearby is Hershey, the town erected by chocolate magnate Milton S. Hershey as a carefully planned, utopian village for his factory workers and their families. The surrounding area, fed by a steady flow of tourists to the Hersheypark amusement park, has attracted top-flight hospitals and cultivated a prosperous air. (The U.S. House of Representatives held “civility retreats” here during the 1990s, but they lapsed due to insufficient interest). Directly south is Middletown, whose leafy, gridded streets and handsome homes give no hint that it is the location of the Three Mile Island nuclear plant, site in 1979 of the worst nuclear accident in American history.

The eastern half of the district has a grittier heritage. In Berks and Schuylkill counties, towns existed solely to mine rich veins of anthracite coal, the nation’s primary energy source in the late 19th and early 20th centuries. These mountain towns were less orderly, filled with tough-talking miners and factory workers—the Pennsylvania that John O’Hara knew growing up and wrote about in the 1930s and 1940s. Although the big companies abandoned the mines long ago, some local entrepreneurs still go deep underground to blast their way into the anthracite. Pottsville is the home of Yuengling lager (known locally as “Vitamin Y”), and produced the Maroons, the team that may have won the 1925 National Football League championship—the league disputed the claim, to Pottsville’s eternal chagrin—and whose ties to coal country are emblematic of the game’s hardscrabble roots. With a disproportionately old population, Schuylkill County had 228,000 people in 1940 and 147,000 in 2007.

Politically, the 17th leans Republican. Harrisburg has been a Republican town from the days when the party seemed to conquer all in Pennsylvania. Republicans held the governorship for all but eight years from 1860 to 1934 and filled the Capitol with Republican patronage hacks. Lebanon County is even more solidly Republican. Schuylkill County, in contrast, has a Democratic heritage from its mining days, though its Democrats tend to take conservative stands on cultural issues. The district voted 58% for Republican President George W. Bush in 2004 and 51% for GOP presidential nominee John McCain in 2008.