Willis Tower new competition by retailing giants such as Kmart, Kohl's, and Walmart. The fortunes of Sears & Roebuck declined in the 1970s as the company lost market share; its management grew more cautious. Nor did the Sears Tower draw as many tenants as Sears had hoped. The tower stood half-vacant for a decade as a surplus of office space was erected in Chicago in the 1980s. In 1990, the law firm of Keck, Mahin & Cate decided to move out of its space in the Sears Tower and into a development that would become 77 West Wacker Drive, rebuffing Sears' attempts
Willis Tower the law firms of Schiff Hardin and Seyfarth Shaw. Morgan Stanley plans to move to the building in 2019, and to become the building's fourth-largest tenant by 2020. In 1969, Sears, Roebuck & Co. was the largest retailer in the world, with about 350,000 employees. Sears executives decided to consolidate the thousands of employees in offices distributed throughout the Chicago area into one building on the western edge of Chicago's Loop. Sears asked its outside counsel, Arnstein, Gluck, Weitzenfeld & Minow (now known as Arnstein & Lehr, LLP) to suggest a location. The firm consulted with local and federal authorities