Sears, Roebuck and Company, colloquially known as Sears, is an American chain of department stores founded by Richard Warren Sears and Alvah Curtis Roebuck in 1892 and 1906. Formerly based at the Sears Tower in Chicago and currently headquartered in Hoffman Estates, Illinois, the operation began as a mail ordering catalog company and began opening retail locations in 1925. The company was bought by the management of the American big box chain Kmart in 2005, the Kmart management formed Sears Holdings upon completion of the merger.