The Boeing Company ( ) (NYSE: BA ) is an American company which makes aircraft and defense items. The company was started in 1916 by William E. Boeing in Seattle, Washington. Boeing has grown to become very big. It bought its main rival, McDonnell Douglas, in 1997. Boeing moved its headquarters from Seattle to Chicago, Illinois in 2001. Boeing is made up of many smaller parts. These parts are called divisions. The divisions are Boeing Commercial Airplanes (BCA); Boeing Defense, Space & Security (BDS); Engineering, Operations & Technology; Boeing Capital; and Boeing Shared Services Group.