1787 - University of Pittsburgh was founded.

Sept. 2, 1786 - Pittsburgh Gazette was the first newspaper in the Ohio Valley area at a cost of six pence.

1794 - Johnny Appleseed (John Chapman) migrated to frontier village of Warren, Pa, now Pittsburgh.

1822 - The Western University of Pennsylvania, located in Pittsburg, commenced operations.

1825 - The Western Theological Seminary of the Presbyterian Church was founded by the General Assembly and located in Allegheny in 1827.

1845 - The Great Fire destroyed many buildings in downtown Pittsburgh.

1849 -  Avery College was established at Allegheny, Pa.

1852 - Completion of the Pennsylvania Railroad between Pittsburgh and Philadelphia.

1871 - Typhoid Fever epidemic in various parts of Allegheny County.

1936 - Devastation of the Great Flood of Pittsburgh and other surrounding areas.