White supremacy is the belief that white people are superior to those of other races. The belief favors the maintenance and defense of any power and privilege held by white people. White supremacy has roots in the now-discredited doctrine of scientific racism and was a key justification for European colonialism.
As a political ideology, it imposes and maintains cultural, social, political, historical or institutional domination by white people and non-white supporters. In the past, this ideology had been put into effect through socioeconomic and legal structures such as the Atlantic slave trade, European colonial labor and social practices, the Scramble for Africa, Jim Crow laws in the United States, the activities of the Native Land Court in New Zealand, the White Australia policies from the 1890s to the mid-1970s, and apartheid in South Africa. This ideology is also today present among neo-Confederates.