Predominating Sex

In the United States
As related to the Aggregate Population
Compiled using estimates from the American Community Survey, 5-Year, 2009-2013
Organization
Census Bureau
Source
American Community Survey, 5-Year
When
2009-2013

The above shows where there are more males than females and vice versa on a diverging color scale. Darker shades of blue represent the former, and darker shades of red represent the latter. Unshaded areas represent counties where there is less than 5 percent more of the opposite sex.

See also this piece on the gender gap from the New York Times.