Today, the mixes among races and ethnicities are diverse, so it is considered preferable to use the term "mixed-race" or simply "mixed" (mezcla).
In Portuguese-speaking Latin America (i.e., Brazil), a milder form of caste system existed, although it also provided for legal and social discrimination among individuals belonging to different races, since slavery for blacks existed until the late 19th century.
Thus the Comte de Montlosier, in exile during the French Revolution, equated class difference in 18th-century France with racial difference. in 1863, and the etymology of the word is tied up with political conflicts during the American Civil War over the abolition of slavery and over the racial segregation of African-Americans.
Borrowing Boulainvilliers' discourse on the "Nordic race" as being the French aristocracy that invaded the plebeian "Gauls", he showed his contempt for the lowest social class, the Third Estate, calling it "this new people born of slaves ... Miscegenation comes from the Latin miscere, "to mix" and genus, "kind". The reference to genus was made to emphasize the supposedly distinct biological differences between whites and non-whites, though all humans belong to the same genus, Homo, and the same species, Homo sapiens.
The differences between related terms and words which encompass aspects of racial admixture show the impact of different historical and cultural factors leading to changing social interpretations of race and ethnicity.
In the United States, miscegenation has referred primarily to the intermarriage between whites and non-whites, especially blacks.
Before the publication of Miscegenation, the word amalgamation, borrowed from metallurgy, had been in use as a general term for ethnic and racial intermixing.
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 With this ruling, these laws were no longer in effect in the remaining 16 states that still had them.