The Top U.S. Supreme Court Decisions of All Time

The Court famously declared: "It is explicitly the province and duty of the Judicial Department to say what the law is." Specifically, the Court ruled that it has both the power and the duty of judicial review, i.e., the power to declare Acts of Congress invalid because contrary to the Constitution.

The case established two fundamental constitutional law principles: (1) Congress has implied powers that are not explicitly enumerated in the Constitution (e.g., the power to establish a national bank); and (2) Federal laws reign supreme over state laws, so states cannot tax federal entities.

The Court applied an expansive interpretation of the Congressional power to regulate interstate commerce, entailing some limitation on state power to do so.

The Court essentially held that war nullifies the First Amendment, so antiwar protesters can be criminally prosecuted.

Thus was born the "clear and present danger" test. (Danger of what? Peace?)

Later cases narrowed the holding, requiring the danger to be "imminent."

This case took the bold move of overruling Plessy v. Ferguson (1896). Plessy had upheld racially segregated schools, describing them as "separate but equal." In Brown v. Board of Education, the Supreme Court declared that racially segregated school are "inherently unequal" and therefore unconstitutional. The decision laid the groundwork for the Civil Rights Movement.

The case established the right to appointed counsel in criminal cases. Later courts would whittle away at the right. Nevertheless, it remains intact at least when a serious crime is involved.

The Court ruled that police need to inform people of their rights before they can conduct custodial interrogations of them. Hence the famous recital, "You have the right to remain, be assisted by an attorney," and so on.

Case established that public school students do not "shed their constitutional rights to freedom of speech…at the schoolhouse gate." A public school may prohibit student speech only if it disrupts the educational process. A school that prohibits a student from wearing a tee-shirt with a "Hell's Kitchen" logo on it simply because a teacher doesn't like, for example, violates the student's First Amendment rights.

In a rare 3-3-3 decision, the Court reached a consensus that females have at least some kind of right of bodily autonomy. The case has also come to represent the idea that the Constitution protects rights that are not explicitly enumerated in it.

The Court struck down an Illinois law that declared children wards of the state upon the mother's death, without any hearing on fitness or proof of neglect on the father's part. After this decision, states can no longer conclusively presume that fathers are unsuitable and unfit to parent children unless supervised by a woman.