1880 January 0
The Allegheny County Light Company, first ambitious electric light concern in the city, began operation with a generator that supplied energy to 40 lights at one time.

1880 January 0
The F. J. Kress Box Company was founded for the manufacture of wooden boxes.

1880 January 0
Assessed valuation of real estate in the city of Pittsburgh was set at $99,600,000.

1880 January 0
Population: 156,389; Allegheny City, 78,682; Allegheny County, 355,869.

1881 January 0
The Homestead mill of the Pittsburgh Bessemer Steel Company, built by Andrew Kloman and a group of other Pittsburgh industrialists, went into operation.

1881 January 0
The Union Switch and Signal Company, a pioneer in the manufacture of automatic signals for trains, was founded by George Westinghouse.

1881 March 0
The Pittsburgh Press Club was organized by newspaper workers at a meeting in the Common Council Chambers at City Hall.

1881 November 15
With Samuel Gompers a prime mover the Federation of Organized Trades and Labor Unions (American Federation of Labor) was organized, in a Pittsburgh convention, by the Knights of Labor and other trade unions, including the Amalgamated Association of Iron and Steel Workers.

1881 November 25
Andrew Carnegie made his first move to create a free library for Pittsburgh; he offered $250,000 on the condition that the city government agree to appropriate $15,000 annually for its maintenance. The city was unable to accept the gift as it had no funds on hand for such a purpose.

1881 November 28
Pittsburgh Catholic College of the Holy Ghost (Duquesne University) received a state charter.

1882 January 0
Historical Society of Western Pennsylvania became the new name for the Old Residents' Association of Pittsburgh and Western Pennsylvania, founded in 1879 as the fourth historical society in the city.

1882 March 6
The Homestead mill of the Pittsburgh Bessemer Steel Company had its first strike when millworkers refused to sign "yellow dog" contracts; violence followed.

1882 May 5
H. C. Frick Coke Company was incorporated with $2,000,000.

1882 May 7
The second courthouse, on Grant's Hill, was destroyed by fire.

1882 June 1
A nationwide strike resulted from a general stoppage of work called by the Amalgamated Association of Iron and Steel Workers in a wage dispute.