1790
| RANK | COUNTY | TOTAL POPULATION | RANK | COUNTY | TOTAL POPULATION | |
| 1 | Philadelphia County | 54,388 | 17 | Adams County | 10,203 | |
| 2 | York County | 37,535 | 16 | Bedford County | 13,132 | |
| 3 | Lancaster County | 36,081 | 4 | Berks County | 30,189 | |
| 4 | Berks County | 30,189 | 6 | Bucks County | 25,216 | |
| 5 | Chester County | 27,829 | 5 | Chester County | 27,829 | |
| 6 | Bucks County | 25,216 | 10 | Cumberland County | 18,208 | |
| 7 | Northampton County | 24,238 | 11 | Dauphin County | 18,155 | |
| 8 | Washington County | 23,892 | 18 | Delaware County | 9,469 | |
| 9 | Montgomery County | 22,918 | 15 | Fayette County | 13,318 | |
| 10 | Cumberland County | 18,208 | 14 | Franklin County | 15,662 | |
| 11 | Dauphin County | 18,155 | 20 | Huntingdon County | 7,558 | |
| 12 | Northumberland County | 17,147 | 3 | Lancaster County | 36,081 | |
| 13 | Westmoreland County | 16,019 | 21 | Luzerne County | 4,892 | |
| 14 | Franklin County | 15,662 | 19 | Mifflin County | 7,562 | |
| 15 | Fayette County | 13,318 | 9 | Montgomery County | 22,918 | |
| 16 | Bedford County | 13,132 | 7 | Northampton County | 24,238 | |
| 17 | Adams County | 10,203 | 12 | Northumberland County | 17,147 | |
| 18 | Delaware County | 9,469 | 1 | Philadelphia County | 54,388 | |
| 19 | Mifflin County | 7,562 | 8 | Washington County | 23,892 | |
| 20 | Huntingdon County | 7,558 | 13 | Westmoreland County | 16,019 | |
| 21 | Luzerne County | 4,892 | 2 | York County | 37,535 |