Stats: stay-at-home moms
America’s Families and Living Arrangements: 2007
Historical Changes in stay-at-Home Mothers: 1969 to 2009
What I REALLY wanted, though, was:
table B23007: PRESENCE OF OWN CHILDREN UNDER 18 YEARS BY FAMILY TYPE BY EMPLOYMENT STATUS. So it also has data for stay-at-home dads as well!
One can go to American FactFinder and find data for fair small geographies.