Sears conglomerate during the mid-20th century, adding Dean Witter and Coldwell Banker real estate in 1981, starting Prodigy as a joint venture with IBM in 1984, and introducing the Discover credit card in 1985. In 1974, Sears completed the 110-story Sears Tower in Chicago, which became the world's tallest building, a title it took from the former World Trade Center towers in New York. Sears moved to the new Prairie Stone Business Park in Hoffman Estates, Illinois, between 1993 and 1995. The Sears Centre is a 10,001-seat multi-purpose arena located in Hoffman Estates adjacent to the Prairie Stone campus. Even though
Center City Tower (Philadelphia) with Comcast Corporation, Philadelphia's most high-profile corporation, in mind. Such a rumor would have been killed on January 5, 2005, the day Comcast Center was officially launched. Center City Tower (Philadelphia) Center City Tower was the working name of a formerly proposed skyscraper in downtown Philadelphia. Designed and proposed by the firm now known as KlingStubbins (designers of Philadelphia's Penn Center and Bell Atlantic Tower), the building would have risen to a height of 1,050 feet (320 m) and 75 stories, making it the tallest building in The United States outside New York and Chicago, surpassing the height of the