Prior to redistricting on March 19, 2018, the 16th congressional district was located in the southeastern part of the state, just west of Philadelphia.

The Supreme Court of Pennsylvania redrew the district in February 2018 after ruling the previous map violated the state constitution due to partisan gerrymandering.

The 16th stretched from the southwestern suburbs of Philadelphia in the east to the Susquehanna River in the west, and north to include areas around Reading.

In 2000, the 16th Congressional District was home to 646,328 residents,[5] according to the U.S. census, and its population has increased since that year.

[1] Pockets of urban areas exist in and around the cities of Lancaster, Reading, and West Chester.