Pennsylvania gained 5 seats in reapportionment following the 1800 census. In redistricting, the number of districts was reduced from 12 to 11, of which four were plural districts with 11 Representatives between them. Most of the new districts had borders that were very different from the previous districts. The new districts were as follows:
Numerous counties had been created between 1800 and 1802 split off from other counties, and several were still administratively attached to other counties.
Note: Many of these counties covered much larger areas than they do today, having since been divided into smaller counties
Election results
Twelve incumbents (9 Democratic-Republicans and 3 Federalists) ran for re-election, many in new districts. William Jones (DR) of the 1st district did not run for re-election. Of those who ran for re-election, all 9 Democratic-Republicans were re-elected, and all 3 Federalists lost to Democratic-Republicans. The six open seats were all won by Democratic-Republicans, returning an all-Democratic-Republican delegation to the 8th Congress.