Primary Care Interventions to Promote Breastfeeding: U.S. Preventive Services Task Force Recommendation Statement.  Ann Intern Med 2008;149 560-564 http://www.annals.org/cgi/content/abstract/149/8/560?etoc 

BFRatesStateAnalysis.pdf

The article looks at, among other variables, the impact of state legislation on breastfeeding rates. Unfortunately, the data they used was through July 2004, so SC falls into one of the "no legislation supporting breastfeeding" categories. For example, ..."in states in which multiple pieces of legislation had been passed supporting breastfeeding, more than 76% of the children were reported to have ever been breastfed compared with only 63.7% of children living in states in which no breastfeeding promotion legislation had been enacted...; similar disparities were evident for children breastfed for at least 6 months (42.4% vs 32.1%)"...

2008 CDC report shows gaps in breastfeeding support