Pittsburgh Steel refers to the steel industry that flourished in Pittsburgh, Pennsylvania, during the late 19th and early 20th centuries. The city became a major center for steel production, thanks to its abundant natural resources, including coal and iron ore. Companies like Carnegie Steel played a significant role in the growth of this industry, contributing to the city's economic development and the rise of the American industrial economy. The steel produced in Pittsburgh was essential for various applications, including construction, manufacturing, and transportation. The industry not only provided jobs for thousands of workers but also helped shape the skyline of cities across the United States. However, the decline of Pittsburgh Steel began in the mid-20th century due to factors like globalization and technological changes.