Mercantile 3201 Old Glenview Rd, Wilmette, IL60091 Mercantile is a real estate brokerage, leasing and management company located on Old Glenview Road in Wilmette. It works…More with residential and commercial leasing and management. It connects people with one of its properties and helps them through the buying or leasing process. Mercantile is a hands-on company and works closely with its clients to make sure that the buying and leasing process runs smoothly. Appointments are mandatory, call the Mercantile office to set up a meeting.