The concept of human rights began as a reaction to the state of human life as humanity emerged from the feudal and baronial eras of history. This led to the basic ethos of universal rights and entitlements regardless of social status. The American and French revolutions in the 18th century saw the first legal manifestations of these concepts as working social practices. They were also the first Western nations without an aristocratic class, a drastic alteration of the social hierarchy which further developed the concept of human rights and led to the abolition of slavery in the following century. The Universal Declaration of Human Rights was adopted by the UN General Assembly in 1948.