In the United States, anti-miscegenation laws (also known as miscegenation laws) were state laws passed by individual states to prohibit miscegenation, nowadays more commonly referred to as interracial marriage and interracial sex. Typically defining miscegenation as a felony, these laws prohibited the solemnization of weddings between persons of different races and prohibited the officiating of such ceremonies. Sometimes, the individuals attempting to marry would not be held guilty of miscegenation itself, but felony charges of adultery or fornication would be brought against them instead. All anti-miscegenation laws banned the marriage of whites and non-white groups, primarily blacks, but often also Native Americans and Asians. In many states, anti-miscegenation laws also criminalized cohabitation and sex between whites and non-whites. In addition, the state of Oklahoma in 1908 banned marriage "between a person of African descent" and "any person not of African descent", and Kentucky and Louisiana in 1932 banned marriage between Native Americans and African Americans. While anti-miscegenation laws are often regarded as a Southern phenomenon, many northern states had anti-miscegenation laws as well.
Although anti-miscegenation amendments were proposed in United States Congress in 1871, 1912-1913 and 1928, a nation-wide law against racially mixed marriages was never enacted. From the 19th century into the 1950s, most US states enforced anti-miscegenation laws. From 1913 to 1948, 30 out of the then 48 states did so. In 1967, the United States Supreme Court unanimously ruled in Loving v. Virginia that anti-miscegenation laws are unconstitutional. With this ruling, these laws were no longer in effect in the remaining 16 states that at the time still enforced them.