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
Library Tower (Chicago) Library Tower (Chicago) Library Tower Chicago is located on 520 S. State Street, Chicago, Illinois, which is the block directly south of the main branch of the Chicago Public Library in the Loop community area. Currently (4/2009) the building has 184 Units. 52 units have been sold and closed. Another 36 are under contract. Apparently, the building was mostly sold unit the economy forced investors to pull out of the building, leaving it largely unsold. Units have been on sale since 2005, with closing first occurring in 2008. There has been substantial price drops from being on the market (1