<P> Thus, the Clause would not be limited to discrimination against African Americans, but would extend to other races, colors, and nationalities such as (in this case) legal aliens in the United States who are Chinese citizens . </P> <P> In its most contentious Gilded Age interpretation of the Equal Protection Clause, Plessy v. Ferguson (1896), the Supreme Court upheld a Louisiana Jim Crow law that required the segregation of blacks and whites on railroads and mandated separate railway cars for members of the two races . The Court, speaking through Justice Henry B. Brown, ruled that the Equal Protection Clause had been intended to defend equality in civil rights, not equality in social arrangements . All that was therefore required of the law was reasonableness, and Louisiana's railway law amply met that requirement, being based on "the established usages, customs and traditions of the people ." Justice Harlan again dissented . "Every one knows," he wrote, </P> <P> that the statute in question had its origin in the purpose, not so much to exclude white persons from railroad cars occupied by blacks, as to exclude colored people from coaches occupied by or assigned to white persons...(I) n view of the Constitution, in the eye of the law, there is in this country no superior, dominant, ruling class of citizens . There is no caste here . Our Constitution is color - blind, and neither knows nor tolerates classes among citizens . </P> <P> Such "arbitrary separation" by race, Harlan concluded, was "a badge of servitude wholly inconsistent with the civil freedom and the equality before the law established by the Constitution ." Harlan's philosophy of constitutional colorblindness would eventually become more widely accepted, especially after World War II . </P>

What test under the equal protection clause is applied to laws involving race or national origin