Polaris Project has just released their report, State Ratings on Human Trafficking Laws 2013. From the press release:
A majority of states still lack laws that protect victims of sex trafficking and help survivors rebuild their lives. Only 12 states have full “safe harbor” laws that protect child victims of sexual exploitation, and another six have passed partial versions of the law; 14 states allow prostitution convictions as a result of trafficking to be removed or “vacated” from criminal records; 22 states mandate or encourage posting of the national human trafficking hotline; and 33 states have passed legislation that provides, funds, or plans for victim assistance and protection services.
Read the full report here (PDF); the analysis here (PDF). Individual state reports are also available.