Short answers, pulled from the story.
Pittsburgh earned the nickname the Steel City because of its dominant role in the U.S. steel industry. By 1910, the city accounted for between one-third and one-half of national steel output. Andrew Carnegie began steel production there in 1875, and in 1901, J. P. Morgan merged Carnegie Steel with other companies to form U.S. Steel.
Pittsburgh has 446 bridges, more than any other city in the United States. This total gives rise to its secondary nickname, the City of Bridges.
Scottish General John Forbes named Pittsburgh in 1758, in honor of British statesman William Pitt, 1st Earl of Chatham. The settlement was incorporated as a borough on the 22nd of April 1794.
Since the 1990s, Pittsburgh has focused on healthcare, education, and technology after the steel and electronics industries collapsed in the early 1980s. The University of Pittsburgh Medical Center is now the city's largest employer, with 48,000 employees, and the region housed 1,600 technology companies by 2010.
Pittsburgh's three major league teams are the Pittsburgh Steelers (NFL, 6 Super Bowl titles), the Pittsburgh Penguins (NHL, 5 Stanley Cup championships), and the Pittsburgh Pirates (MLB, 5 World Series titles). All three share the city's official colors of black and gold.
Pittsburghese is the local English dialect, shaped by Scots-Irish, German, Eastern European, and African American linguistic influences. Distinctive terms include "yinz" (you all), "slippy" (slippery), "redd up" (clean up), and "gum bands" (rubber bands). The New York Times described Pittsburgh as "the Galapagos Islands of American dialect."