One of the most historic teams, the Pittsburgh Steelers, was founded in 1933 as the Pittsburgh Pirates, and seven years later they took on their current name. They are the most successful American football team along with the New England Patriots, with 6 Super Bowl championships. During World War II, they were forced to merge with other NFL teams, such as the Philadelphia Eagles and the Chicago Cardinals, due to a shortage of players. Outstanding draft picks from 1969 to 1974, selecting a total of nine Hall of Famers, combined with coach Chuck Noll, led the Steelers to four Super Bowl championships in the 1970s. During this period, the team's defensive line was so formidable that it became known as the "Steel Curtain" and was a key weapon in the Steelers' successes. With the gradual retirement of their drafted players, the Steelers experienced a period without much success until the mid-2000s, when they won their last two Super Bowl championships, under one of the longest tenured NFL head coaches, Mike Tomlin.