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.
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.
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.
The Nazi ban on interracial sexual relations and marriages was enacted in September 1935 as part of the Nuremberg Laws, the Gesetz zum Schutze des deutschen Blutes und der deutschen Ehre (The Law for the Protection of German Blood and German Honour).
The Nuremberg Laws classified Jews as a race, and forbade extramarital sexual relations and marriage between persons classified as "Aryan" and "non-Aryan".