The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001. Boeing is made up of multiple business units, which are Boeing Commercial Airplanes ; Boeing Defense, Space & Security ; Engineering, Operations & Technology; Boeing Capital; and Boeing Shared Services Group.