http://www.censusscope.org/us/chart_popl.html http://www.censusscope.org/us/chart_popl.html http://www.censusscope.org/us/chart_popl.html census http://www.censusscope.org/us/chart_popl.html 179 million in 1960 doubled http://www.censusscope.org/us/chart_popl.html http://www.censusscope.org/us/chart_popl.html http://www.censusscope.org/us/chart_popl.html http://www.censusscope.org/us/chart_popl.html doubled http://www.censusscope.org/us/chart_popl.html