1890
| RANK | COUNTY | TOTAL POPULATION | RANK | COUNTY | TOTAL POPULATION | |
| 1 | Philadelphia County | 1,046,964 | 49 | Adams County | 33,486 | |
| 2 | Allegheny County | 551,959 | 2 | Allegheny County | 551,959 | |
| 3 | Luzerne County | 201,203 | 35 | Armstrong County | 46,747 | |
| 4 | Schuylkill County | 154,163 | 31 | Beaver County | 50,077 | |
| 5 | Lancaster County | 149,095 | 41 | Bedford County | 38,644 | |
| 6 | Lackawanna County | 142,088 | 7 | Berks County | 137,327 | |
| 7 | Berks County | 137,327 | 20 | Blair County | 70,866 | |
| 8 | Montgomery County | 123,290 | 26 | Bradford County | 59,233 | |
| 9 | Westmoreland County | 112,819 | 21 | Bucks County | 70,615 | |
| 10 | York County | 99,489 | 28 | Butler County | 55,339 | |
| 11 | Dauphin County | 96,977 | 24 | Cambria County | 66,375 | |
| 12 | Chester County | 89,377 | 67 | Cameron County | 7,238 | |
| 13 | Erie County | 86,074 | 42 | Carbon County | 38,624 | |
| 14 | Northampton County | 84,220 | 38 | Centre County | 43,269 | |
| 15 | Fayette County | 80,006 | 12 | Chester County | 89,377 | |
| 16 | Lehigh County | 76,631 | 47 | Clarion County | 36,802 | |
| 17 | Northumberland County | 74,698 | 23 | Clearfield County | 69,565 | |
| 18 | Delaware County | 74,683 | 52 | Clinton County | 28,685 | |
| 19 | Washington County | 71,155 | 46 | Columbia County | 36,832 | |
| 20 | Blair County | 70,866 | 25 | Crawford County | 65,324 | |
| 21 | Bucks County | 70,615 | 33 | Cumberland County | 47,271 | |
| 22 | Lycoming County | 70,579 | 11 | Dauphin County | 96,977 | |
| 23 | Clearfield County | 69,565 | 18 | Delaware County | 74,683 | |
| 24 | Cambria County | 66,375 | 55 | Elk County | 22,239 | |
| 25 | Crawford County | 65,324 | 13 | Erie County | 86,074 | |
| 26 | Bradford County | 59,233 | 15 | Fayette County | 80,006 | |
| 27 | Mercer County | 55,744 | 66 | Forest County | 8,482 | |
| 28 | Butler County | 55,339 | 30 | Franklin County | 51,433 | |
| 29 | Tioga County | 52,313 | 64 | Fulton County | 10,137 | |
| 30 | Franklin County | 51,433 | 51 | Greene County | 28,935 | |
| 31 | Beaver County | 50,077 | 48 | Huntingdon County | 35,751 | |
| 32 | Lebanon County | 48,131 | 39 | Indiana County | 42,175 | |
| 33 | Cumberland County | 47,271 | 37 | Jefferson County | 44,005 | |
| 34 | McKean County | 46,863 | 60 | Juniata County | 16,655 | |
| 35 | Armstrong County | 46,747 | 6 | Lackawanna County | 142,088 | |
| 36 | Venango County | 46,640 | 5 | Lancaster County | 149,095 | |
| 37 | Jefferson County | 44,005 | 44 | Lawrence County | 37,517 | |
| 38 | Centre County | 43,269 | 32 | Lebanon County | 48,131 | |
| 39 | Indiana County | 42,175 | 16 | Lehigh County | 76,631 | |
| 40 | Susquehanna County | 40,093 | 3 | Luzerne County | 201,203 | |
| 41 | Bedford County | 38,644 | 22 | Lycoming County | 70,579 | |
| 42 | Carbon County | 38,624 | 34 | McKean County | 46,863 | |
| 43 | Warren County | 37,585 | 27 | Mercer County | 55,744 | |
| 44 | Lawrence County | 37,517 | 57 | Mifflin County | 19,996 | |
| 45 | Somerset County | 37,317 | 56 | Monroe County | 20,111 | |
| 46 | Columbia County | 36,832 | 8 | Montgomery County | 123,290 | |
| 47 | Clarion County | 36,802 | 62 | Montour County | 15,645 | |
| 48 | Huntingdon County | 35,751 | 14 | Northampton County | 84,220 | |
| 49 | Adams County | 33,486 | 17 | Northumberland County | 74,698 | |
| 50 | Wayne County |