Mildred Loving, who recently passed away, was responsible for the US Supreme Court ruling antimiscegenation laws in Virginia illegal. Here is a description and e-copy of Chief Justice Earl Warren's ruling on the case, Loving v Virginia. Key quote from the ruling:
"Under our Constitution the freedom to marry or not marry a person of another race resides with the individual and cannot be infringed upon by the state."
Ironically, Loving's death comes close to the "big speech" by Senator John McCain on "activist judges." If laws and social policy were left solely to legislatures, nutjobs voted into power could make ordinary citizens' life hell. Apparently "states' rights" were at least at one time - and maybe even today - code for racial discrimination laws - see this write-up and links therein.