Booz Allen Hamilton Inc.

is an American public consulting firm headquartered in McLean, Fairfax County, Virginia, with 80 other offices throughout the United States. Ralph Shrader is its Chairman and Chief Executive Officer. The firm was founded by Edwin Booz in Chicago circa 1914. It is listed as number 438 in the 2011 Fortune 500 and is listed as the 9th largest US Government contractor (the largest for consulting services) by Washington Technology magazine in 2011