Clairton is a city in Allegheny County, Pennsylvania, United States, along the Monongahela River. It is part of the Pittsburgh Metropolitan Area. The population was 6,796 at the 2010 census. Under Pennsylvania legal classifications for local governments, Clairton is considered a third-class city. It is home to Clairton Works, the largest coke manufacturing facility in the United States.
The city was the setting for the movie The Deer Hunter (1978), although none of the movie was actually filmed there (other mill towns in the Monongahela River Valley and elsewhere in the tri-state area were used). Even the opening scene, which features a large sign saying "Welcome to Clairton, City of Prayer," was shot in Mingo Junction, Ohio, although its verbiage is based on smaller signs posted at the city's boundaries during the mid 1960s (as a response to the Supreme Court's 1963 ban on sponsored school prayer).
Clairton’s existence began just after the turn of the 20th century when the Crucible Steel Company acquired a large tract along the west side of the Monongahela River, about south of Pittsburgh. Soon after, the Carnegie Steel Co. (later U.S. Steel) built an integrated steel mill and coke production facility, which eventually became one of the world's largest.
The site had more than of level land suitable for a large industrial complex. On April 12, 1903, Clairton was incorporated as a borough, and on January 1, 1922, Clairton was incorporated as a City of the Third Class with a population of approximately 11,000. This incorporation was prompted by industry, which was taxed by the three boroughs - Clairton, Wilson and North Clairton - which were chartered separately prior to the incorporation of the City of Clairton.
During the next several decades, growth and advancement indicated a thriving city. As the steel mill and coke production facilities expanded, the population of Clairton grew. Clairton took on a life of its own, including a business district and educational, religious, and cultural facilities.
The city peaked in the late 1950s when the population approached 25,000. According to the U.S. Census Bureau, the official population in 1950 was 19,652, but by 1960 had begun its first-ever decline when the number fell to 18,389. By 1970, the population was down to 15,051, signaling a trend that has continued until today.
In the late 1950s, Clairton High School (CHS) had a large student body, and the city had a "feeder" system of public and parochial elementary schools. The CHS student body was soon siphoned off, however, by new schools in Elizabeth Borough, Snowden Township, and Jefferson Borough. During the mid 1950s and into the 1960s, CHS was a Class AAA competitor in the formidable Western Pennsylvania Interscholastic Athletic League (WPIAL), playing against high schools in other mill towns up and down the Monongahela River Valley.
With the decline of the steel industry in the 1980s, Clairton began to experience severe problems in its employment and tax base, which spurred a major economic shock to the community. In 1988, Clairton was designated a distressed municipality by Pennsylvania's Department of Community Affairs (DCA). Pursuant to Act 47 of 1987 (the Financially Distressed Municipalities Act), DCA commissioned the development of a recovery plan for Clairton. By 1988, the Clairton School District had consolidated its entire system into a single building (a remodeled version of the high school) and closed its other schools. Clairton High now competes at the Class A level in the WPIAL. The high school football team has had national prominence for recent success.