
A lot can change in 118 years, as a new map from the Pennsylvania State Data Center shows.
The choropleth map shows how the population of Pennsylvania’s 67 counties has changed over the last century, from 1900-2018.
Let’s take a closer look:
Booming counties
Large jumps in population growth are mostly relegated to the state’s eastern border counties.
These are the counties with the largest growth in population over the last century:
Bucks County … 782.4% growth since 1900.
Monroe County … 701% growth since 1900.
Pike County … 538.1% growth since 1900.
Montgomery County … 496.1% growth since 1900.
Delaware County … 496% growth since 1900.
Chester County … 445.5% growth since 1900.
On the decline
Ten Pennsylvania counties have seen a decrease in population growth since 1900.
Counties with declining population growth are:
Sullivan County … -50% change in population.
Potter County … -45.7% change in population.
Cameron County … -36.3% change in population.
Forest County … -34.1% change in population.
Jefferson County … -26.2% change in population.
McKean County … 20.2% change in population.
Schuylkill County … -17.8% change in population.
Tioga County … -17% change in population.
Elk County … -8.3% change in population.
Clearfield County … -1.5% change since 1900.
Population stagnation
While some counties have seen exponential growth in their populations since 1900, a handful have remained virtually unchanged.
The counties with little change include:
Northumberland County … 0.2% change since 1900.
Susquehanna County … 1.4% change since 1900.
Warren County … 1.4% change since 1900.
Bradford County … 2.4% change since 1900.
Venago County … 3.3% change since 1900.
Lackawanna County … 8.8% change since 1900.