Pennsylvania
Adams formed 22 Jan 1800 from York.
Alleghany formed 24 Sep 1788 from Westmoreland & Washington; Armstrong, Beaver, Butler, Crawford, Erie, Mercer, Venango, Warren all formed from it in 1800
Armstrong formed 12 Mar 1800 from Allegheny, Washington & Westmoreland; Clarion formed from it 1839.
Beaver formed 12 Mar 1800 from Allegheny & Washington; Lawrence formed from it 1849.
Bedford formed 9 Mar 1771 from Cumberland; Northumberland 1772, Westmoreland 1773, Huntington 1787, Somerset 1795, Camoria 1804, Blair 1846, Fulton 1850 formed from it
Berks formed 14 Oct 1751 from Bucks, Lancaster & Philadelphia; Schuylkill 1811 formed from it
Blair
Bradford
Bucks formed 10 Mar 1682 from Colonial lands; Berks & Northampton formed from it in 1751
Butler
Cambria
Cameron
Carbon
Center formed 13 Feb 1800 from Lycoming, Mifflin & Northumberland; Clinton formed from it in 1839
Chester formed 10 Mar 1682 from Colonial lands; Lancaster 1728 and Delaware 1789 formed from it
Clarion formed 11 Mar 1839 from Venango and Armstrong.
Clearfield formed 26 Mar 1804 from Lycoming & Northumberland; Elk formed from it 1843
Clinton
Columbia formed 22 Mar 1813 from Northumberland; Montour formed from it 1850.
Crawford formed 12 March 1800 from Allegheny
Cumberland formed 17 Jan 1750 from Lancaster; Bedford 1771, Franklin 1784, Mifflin 1789 and Perry 1820 formed from it.
Dauphin formed 4 Mar 1785 from Lancaster; Lebanon formed from it 1813.
Delaware formed 26 Sep 1789 from Chester.
Elk
Erie
Fayette formed 26 Sep 1783 from Westmoreland
Forest
Franklin formed 9 Sep 1784 from Cumberland
Fulton
Greene formed 9 Feb 1796 from Washington
Huntington formed 20 Sep 1787 from Bedford; Cambria 1805 and Blair 1846 formed from it.
Indiana formed 30 Mar 1803 from Lycoming & Westmoreland.
Jefferson
Juniata formed 2 Mar 1831 from Mifflin
Lackawanna
Lancaster formed 14 Oct 1728 from Chester; York 1749, Cumberland 1750, Berks 1751, Northumberland 1772, Dauphin 1785, Lebanon 1813 formed from it.
Lawrence
Lebanon formed 16 Feb 1813 from Dauphin & Lancaster.
Lehigh formed from Northampton 6 Mar 1812
Luzerne formed 25 Sep 1786 from Northumberland; Bradford, Ontario, Lackawanna & Susquehanna 1810, Wyoming 1842 formed from it.
Lycoming formed 13 Apr 1795 from Northumberland; Armstrong, Venango, Warren, Center 1800, Indiana 1803, Tioga, Clearfield, McKean, Jefferson, Potter 1804, Bradford 1810, Clinton 1839, Sullivan 1847 formed from it.
McKean
Mercer
Mifflin formed 19 Sep 1789 from Cumberland and Northumberland; Center 1800 and Juniata 1831 formed from it.
Monroe
Montgomery formed 10 Sep 1782 from Philadelphia
Montour
Northampton formed 14 Oct 1751 from Bucks; Wayne 1798, Schuylkill 1811, Lehigh 1812, Monroe 1836 and Carbon 1843 formed from it.
Northumberland formed 21 Mar 1772 from Lancaster & Bedford; Luzerne 1786. Mifflin 1789, Lycoming 1795, Center 1800, Clearfield 1804, Union & Columbia 1813 formed from it.
Ontario
Perry formed 22 Mar 1820 from Cumberland.
Philadelpia formed 10 Mar 1682 from Colonial lands; Berks 1751 and Montgomery 1784 formed from it.
Pike
Potter
Schuylkill formed 1 Mar 1811 from Berks and Northampton.
Snyder formed 2 Mar 1855 from Union.
Somerset formed 17 Apr 1795 from Bedford; Cambria formed from it 1804.
Sullivan formed 15 Mar 1847 from Lycoming.
Susquehanna formed 21 Feb 1810 from Luzerne.
Tioga formed 26 Mar 1804 from Lycoming.
Union formed 22 Mar 1813 from Northumberland; Snyder formed from it 1855
Venango formed 12 Mar 1800 from Allegheny & Lycoming; Clarion 1839 & Forest 1848 formed from it.
Warren formed 12 Mar 1800 from Allegheny and Lycoming.
Washington formed 26 Mar 1781 from Westmoreland; Allegheny 1788, Greene 1796, Beaver1800 formed from it.
Westmoreland formed 26 Feb 1773 from Bedford; Washington 1781, Fayette 1783, Allegheny 1788, Armstrong 1800, Indiana 1801 formed from it.
Wyoming formed 4 Apr 1842 from Luzerne.
York formed 14 Oct 1749 from Lancaster; Adams formed from it 1800.
Link to Pennsylvania Deweeses
Link to Pennsylvania Bothwells
Link to Pennsylvania Darrs
Bedford Co
Link to Pennsylvania Lusks
Berks
Cumberland
Fayette
Lancaster
Lebanon
Lehigh
Montgomery
Northampton
Northumberland
Philadelphia
Westmoreland
York