A racial hierarchy is a system of stratification that is based on the belief that some racial groups are superior to other racial groups. At various points of history, racial hierarchies have featured in societies, often being formally instituted in law, such as in the Nuremberg Laws in Nazi Germany. Generally, those who support racial hierarchies believe themselves to be part of the 'superior' race and base their supposed superiority on pseudo-biological, cultural or religious arguments. However, systems of racial hierarchy have also been widely rejected and challenged, and many, such as Apartheid have been abolished. The abolition of such systems has not stopped debate around racial hierarchy and racism more broadly. Asia Liberia Liberia confers nationality solely on the basis of race. Under the current Liberian constitution, only persons of Black African origins (Negroes) may obtain citizenship, although Liberian law allows members of other races to hold permanent residency status. Features of the first constitution that have been upheld include: Article V, Section 13 of the 1847 Constitution which states: "The great object of forming these Colonies, being to provide a home for the dispersed and oppressed children of Africa, and to regenerate and enlighten this benighted continent, none but persons of colour shall be eligible to citizenship in this Republic." The phrasing "persons of colour" was changed to "Negroes or persons of Negro descent" in a 1955 revision. United States Slavery From the founding of the United States until after the Civil War, racial hierarchy was visible through the racially-based Slavery in the United States which had taken root before American independence. Though many abolitionists had campaigned for slavery to be ended, there was much resistance from those who benefitted economically, as well as those who believed it was 'natural' for racially based reasons-these two groups were not mutually exclusive. In order to maintain and defend slavery, pro-slavery writers organized a "planter liberalism" by combining paternalist and liberal views into an ideology that could be understood by both slave-holding and non-slave-holding citizens. Their ideology was based on familiar domestic relationships. These views later paved the way for white Southern planters to keep racial conditions as close to slavery as legally possible after the Civil War during the Reconstruction era. The Thirteenth Amendment, which abolished legal slavery in 1865, did not remove institutionalised racial hierarchy. In the southern states which had retained slavery until the end of the Civil