33 years.
Anti-miscegenation laws were a part of American law since before the United States was established and remained so until ruled unconstitutional in 1967 by the U.S. Supreme Court in Loving v. Virginia. Prior to the California Supreme Court's ruling in Perez v. Sharp (1948), no court in the United States had ever struck down a ban on interracial marriage. In 1967, the United States Supreme Court unanimously ruled in Loving v. Virginia that anti-miscegenation laws are unconstitutional, relying partially on Perez. With this ruling, these laws were no longer in effect in the remaining 16 states that at the time still enforced them. At the time that anti-miscegenation laws were ruled unconstitutional by the U.S. Supreme Court, 16 states still had laws prohibiting interethnic marriage. Those laws were not completely repealed until November 2000, when Alabama became the last state to repeal its law. The constitutionality of anti-miscegenation laws was upheld by the U.S. Supreme Court in the 1883 case Pace v. Alabama (106 U.S. 583). The Supreme Court ruled that the Alabama anti-miscegenation statute did not violate the Fourteenth Amendment to the United States Constitution. [edit] Alabama gets that banjo off its knee. In November 2000, Alabama became the last state to overturn a law banning interracial marriage. The one-time home of George Wallace and Martin Luther King Jr. had held onto the provision for 33 years after the Supreme Court declared anti-miscegenation laws unconstitutional. For example: The 1967 Supreme Court decision on Loving v. Virginia made American a nti-miscegenation laws unconstitutional. Until that point, 16 states, all in the South (see below) had laws banning mixed 'race' marriages. Note also, however, that many other states had only recently overturned their laws.
https://en.wikipedia.org/wiki/Anti-miscegenation_laws_in_the_United_States https://en.wikipedia.org/wiki/Anti-miscegenation_laws_in_the_United_States http://psychology.wikia.com/wiki/Miscegenation http://academic.luzerne.edu/shousenick/104--TobiasWolff_SayYes_MiscegenationLaws.doc http://rationalwiki.org/wiki/Interracial_marriage_in_the_United_States http://www.webpages.uidaho.edu/engl_258/Lecture%20Notes/american_antimiscegenation.htm
what year did miscegenation become unconstitutional