1860
| RANK | COUNTY | TOTAL POPULATION | RANK | COUNTY | TOTAL POPULATION | |
| 1 | Philadelphia County | 565,529 | 36 | Adams County | 28,006 | |
| 2 | Allegheny County | 178,831 | 2 | Allegheny County | 178,831 | |
| 3 | Lancaster County | 116,314 | 25 | Armstrong County | 35,797 | |
| 4 | Berks County | 93,818 | 33 | Beaver County | 29,140 | |
| 5 | Luzerne County | 90,244 | 40 | Bedford County | 26,736 | |
| 6 | Schuylkill County | 89,510 | 4 | Berks County | 93,818 | |
| 7 | Chester County | 74,578 | 37 | Blair County | 27,829 | |
| 8 | Montgomery County | 70,500 | 14 | Bradford County | 48,734 | |
| 9 | York County | 68,200 | 10 | Bucks County | 63,578 | |
| 10 | Bucks County | 63,578 | 26 | Butler County | 35,594 | |
| 11 | Westmoreland County | 53,736 | 32 | Cambria County | 29,155 | |
| 12 | Erie County | 49,432 | 47 | Carbon County | 21,033 | |
| 13 | Crawford County | 48,755 | 38 | Centre County | 27,000 | |
| 14 | Bradford County | 48,734 | 7 | Chester County | 74,578 | |
| 15 | Northampton County | 47,904 | 43 | Clarion County | 24,988 | |
| 16 | Washington County | 46,805 | 49 | Clearfield County | 18,759 | |
| 17 | Dauphin County | 46,756 | 51 | Clinton County | 17,723 | |
| 18 | Lehigh County | 43,753 | 41 | Columbia County | 25,065 | |
| 19 | Franklin County | 42,126 | 13 | Crawford County | 48,755 | |
| 20 | Cumberland County | 40,098 | 20 | Cumberland County | 40,098 | |
| 21 | Fayette County | 39,909 | 17 | Dauphin County | 46,756 | |
| 22 | Lycoming County | 37,399 | 31 | Delaware County | 30,597 | |
| 23 | Mercer County | 36,856 | 63 | Elk County | 5,915 | |
| 24 | Susquehanna County | 36,267 | 12 | Erie County | 49,432 | |
| 25 | Armstrong County | 35,797 | 21 | Fayette County | 39,909 | |
| 26 | Butler County | 35,594 | 65 | Forest County | 898 | |
| 27 | Indiana County | 33,687 | 19 | Franklin County | 42,126 | |
| 28 | Wayne County | 32,239 | 60 | Fulton County | 9,131 | |
| 29 | Lebanon County | 31,831 | 44 | Greene County | 24,343 | |
| 30 | Tioga County | 31,044 | 35 | Huntingdon County | 28,100 | |
| 31 | Delaware County | 30,597 | 27 | Indiana County | 33,687 | |
| 32 | Cambria County | 29,155 | 50 | Jefferson County | 18,270 | |
| 33 | Beaver County | 29,140 | 52 | Juniata County | 16,986 | |
| 34 | Northumberland County | 28,922 | 3 | Lancaster County | 116,314 | |
| 35 | Huntingdon County | 28,100 | 45 | Lawrence County | 22,999 | |
| 36 | Adams County | 28,006 | 29 | Lebanon County | 31,831 | |
| 37 | Blair County | 27,829 | 18 | Lehigh County | 43,753 | |
| 38 | Centre County | 27,000 | 5 | Luzerne County | 90,244 | |
| 39 | Somerset County | 26,778 | 22 | Lycoming County | 37,399 | |
| 40 | Bedford County | 26,736 | 61 | McKean County | 8,859 | |
| 41 | Columbia County | 25,065 | 23 | Mercer County | 36,856 | |
| 42 | Venango County | 25,043 | 54 | Mifflin County | 16,340 | |
| 43 | Clarion County | 24,988 | 53 | Monroe County | 16,758 | |
| 44 | Greene County | 24,343 | 8 | Montgomery County | 70,500 | |
| 45 | Lawrence County | 22,999 | 57 | Montour County | 13,053 | |
| 46 | Perry County | 22,793 | 15 | Northampton County | 47,904 | |
| 47 | Carbon County | 21,033 | 34 | Northumberland County | 28,922 | |
| 48 | Warren County | 19,190 | 46 | Perry County | 22,793 | |
| 49 | Clearfield County | 18,759 | 1 | Philadelphia County | 565,529 | |
| 50 | Jefferson County |