massive government spending industrial production was increased War Production Board http://www.pbs.org/thewar/at_home_war_production.htm industrial production was increased (REF: PBS.org) writing for PBS http://www.pbs.org/thewar/at_home_war_production.htm Only 139 more were made converted several industries went out and bought General Motors more than 3 million cars 193,000 artillery pieces converted several industries writing for PBS Only 139 more were made http://www.pbs.org/thewar/at_home_war_production.htm President Roosevelt ordered it War Production Board http://www.pbs.org/thewar/at_home_war_production.htm employed by jobs related to the war converted several industries http://www.pbs.org/thewar/at_home_war_production.htm orders of magnitude more complex War Production Board