Using county-level Census data, I’ve mapped the marriage status of women who gave birth in the past 12 months. The data gathered are based on women aged 15-50. Women are considered married even if they are separated or their spouses are absent. Women who are not married may be single, divorced, or widowed. Not all counties had sufficient data, and in some of the sparsely populated counties, zero births were recorded by the Census.

The clear trend is that states in the South have higher percentages of unwed women giving birth. New Mexico also has a large cluster of low marriage percentage (purple) counties.

I was interested to see whether counties’ overall marriage rates were influencing the data. I graphed the marriage status of women who had not given birth in the past 12 months against the status of those who had given birth. There is a very weak positive correlation (r^2 = 0.15). So there is minimal influence from the overall marriage rate. There are some counties where most women are married, but those who recently had a baby tend not to be married. And there are some counties where married women are having children, but there are few married women in the county.

Data source: http://factfinder2.census.gov/faces/nav/jsf/pages/index.xhtml (table B13002)