Civil War and After

When the Civil War began in 1861, the state wholeheartedly supported the Union. Some 338,000 men from Pennsylvania served in the Union Army. The state's industrial power and its railroad system contributed significantly to the economic strength of the northern states. Confederate troops entered Pennsylvania three times during the war. Chambersburg was raided in 1862 and 1864. The war's most decisive battle was fought at Gettysburg, July 1–3, 1863. (

A period of industrial and commercial expansion followed the Civil War. Development of Pennsylvania's vast coalfields was rapid as the demand for coal, especially by the railways and the iron and steel industry, grew. Large numbers of immigrants from eastern and western Europe came to work in the mines and factories. Petroleum, first discovered by Edwin L. Drake at Titusville in 1859, developed into a valuable resource. Industrial power and wealth became concentrated in the hands of a few men, among them Andrew Carnegie and Charles M. Schwab in the steel industry, Henry Clay Frick in coal mining, and J. Pierpont Morgan and Thomas Mellon in finance.

Labor unionism and labor troubles accompanied the state's industrial growth, as workers sought higher wages, shorter hours, and better working conditions. The most serious disorders during the nationwide railway strike of 1877 were in Pittsburgh, where workers struck against the powerful Pennsylvania Railroad. The Federation of Organized Trades and Labor Unions (later the American Federation of Labor) was organized in Pittsburgh in 1881. In 1892 there was a major strike at the Carnegie Steel Company steel mills, with resulting violence at Homestead. Strikes in the anthracite coalfields took place in 1897 and 1902. ( Important leaders in the early labor movement in the state were Terence K. Powderly of the Knights of Labor and John Mitchell of the United Mine Workers.

Meanwhile, in 1889, Pennsylvania had suffered its worst natural disaster—the Johnstown flood, in which more than 2,200 lives were lost. (

Modern Development. Throughout the late 19th and the early 20th century, Pennsylvania was ruled by a Republican machine under bosses Simon and J. Donald Cameron, Matthew S. Quay, and Boies Penrose. The machine was allied with the big steel, oil, and rail interests. In the 1890's, reformist elements in the state began protesting corruption in government and the concentration of economic power. Although some social and political reforms took place during the Progressive era preceding World War I, reform of state government did not begin until after Gifford Pinchot, an associate of President Theodore Roosevelt, was elected governor in 1922. During his two terms in office (1923–27 and 1931–35), he reorganized the state's administration, rooting out corruption and making government more efficient.

Pennsylvania made a significant contribution to the war effort during World War I, with its mines, mills, and men. About 370,000 Pennsylvanians served in the armed forces. Pittsburgh was called the “arsenal of the world" because of its steel production. In the 1920's, however, the steel and coal industries both began to decline. During the Great Depression of the 1930's, unemployment was widespread. The production demands of World War II ended the period of stagnation, bringing full employment and prosperity. The state produced more than 30 per cent of the nation's coal and steel during the war.

In the first years after the war, Pennsylvania suffered a decline in its major industries, chiefly steel and coal, with a resulting loss of jobs. The Pennsylvania Industrial Development Authority was created in the late 1950's to recruit new industries and encourage economic expansion. It aided diversification and increased employment. However, the economy remained sluggish in the 1960's and 1970's. Population barely grew in the 1970's, and the state slipped from third to fourth largest in the nation.

In 1979 an accident at the Three Mile Island nuclear power plant near Harrisburg released radioactive gases into the atmosphere and caused widespread concern about the safety of nuclear power plants.

Pennsylvania's industries suffered during the economic recession of the early 1980's. In the late 1980's, however, increased demand for coal and the growth of the electronics industry and various service industries aided economic recovery. However, the recession of the early 1990's slowed growth, particularly in the industrialized western counties.

By the end of the 1990's, however, the economy of Pennsylvania was healthy after a shift from manufacturing activities to stronger ones such as medical, financial, cultural, and educational institutions; workers were also able to make the shift, improving major metropolitan areas. The creation of heritage parks, which document the roles of various regions in the state's industrial development, created thousands of jobs and even greater finances. This paralleled the state's work to preserve historical sites and both projects contributed to an increase in the tourism industry.