The district contains all of Adams, Bedford, Blair, Cambria, Franklin, Fulton, Huntingdon, Juniata, Mifflin, and Perry counties.

With a Cook Partisan Voting Index rating of R+25, it is the most Republican district in Pennsylvania.

[1] Prior to February 2018, the district was located in southeastern Pennsylvania, covering eastern Montgomery County and Northeast Philadelphia.

The Supreme Court of Pennsylvania redrew the district in February 2018 after ruling the previous map unconstitutional.

However, the brand of Republicanism in southeastern Pennsylvania was a moderate one, and the district, like the Philadelphia suburbs as a whole, became friendlier to Democrats during the 1990s as the national party veered to the right.

She was defeated in 1994 by Republican Jon D. Fox, but Joe Hoeffel regained the seat for the Democrats in 1998.