ial Times to 1970, Part il and per White House OMB. GDP prior to 1930 per Louis Johnston and Samuel H. Williamson, “What Was the U.S. GDP Then?" KP MeasuringWorth, 2010. GDP post 1930 per White House OMB. Neither federai spending nor GDP data are adjusted for inflation. (aE wew. kpcb.com USA Inc. | Summary KP