History of Pittsburgh

steelworks of Merthyr migrated to the city following the civil strife and aftermath of the Merthyr Riots of 1831. By the 1840s, Pittsburgh was one of the largest cities west of the Allegheny Mountains. A great fire burned over a thousand buildings in 1845, but the city rebuilt. By 1857, Pittsburgh's 1,000 factories were consuming 22,000,000 bushels of coal yearly.

The American Civil War boosted the city's economy with increased production of iron and armaments. Steel production began by 1875, when Andrew Carnegie founded the Edgar Thomson Steel Works in North Braddock, which eventually evolved into the Carnegie Steel Company. The success and growth of Carnegie Steel is attributed to Henry Bessemer who had developed the Bessemer Process to facilitate the low cost mass production of steel.

In 1901, the U.S. Steel Corporation was formed. By 1911 Pittsburgh was the nation's eighth largest city accounting for between a third and a half of the national steel output. The city's population swelled to over a half million, many of whom were immigrants from Europe who arrived via the great migration through Ellis Island. In 1940, non-Hispanic whites were 90.6% of the city's population. The Great Migration from the South resulted in a large increase in Pittsburgh's African-American population. Ninety-five percent of the African-American population working in the steel mills were doing unskilled labor and were not well established. During World War II, Pittsburgh produced 95 million tons of steel. By this time, the pollution from burning coal and steel production created a black fog (or smog), which even a century earlier had induced author writer James Parton to dub the city " @#!*% with the lid off".

Following the war, the city launched a clean air and civic revitalization project known as the