Why was "tantrum" trending last week?
1932 as a noun, 1938 as an adjective, from race (n.2); racism is first attested 1936 (from French racisme, 1935), originally in the context of Nazi theories. But they replaced earlier words, racialism (1871) and racialist (1917), both often used early 20c. in a British or South African context. In the U.S., race hatred, race prejudice had been used, and, especially in 19c. political contexts, negrophobia.