In 1681 William Penn, an English Quaker, received a royal proprietorship to what became Pennsylvania. Almost a century later, his capital, Philadelphia, witnessed the signing of the Declaration of Independence and the framing of the U.S. Constitution. European immigrants, many of them iron- and steelworkers, founded trade unions that evolved into the American Federation of Labor (AFL) and Congress of Industrial Organizations (CIO). German, Slav, and Italian neighborhoods enliven Pittsburgh today.

Still heavily industrialized, Pennsylvania produces much of the nation's steel, but retail, manufacturing, and other services employ more workers.