Landmark cases are those that have had a long-term impact on how a law is applied, often involving your personal rights and liberties. A landmark case is a court case that has been researched for its historical and legal significance because it is significant to the country's history. Importance: The Brown decision is heralded as a landmark decision in Supreme Court history, overturning Plessy v. Ferguson (1896) which had created the "separate but equal" doctrine.
Separation of powers, therefore, refers to the division of government responsibilities into distinct branches to limit any one branch from exercising the core functions of another.