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
Chicago Water Tower Pumping Station, it drew clean water from water cribs in Lake Michigan. The tower gained prominence after the Great Chicago Fire of 1871. While some incorrectly believe that the tower was the only building to survive the fire, a few other buildings in the burned district survived along with the tower. The tower was the only public building in the burned zone to survive, and is one of just a few of the surviving structures still standing. In the years since the fire, the tower has become a symbol of old Chicago and of the city's recovery from the fire.