1803: Marbury v. Madison established the principle of judicial review, giving the Supreme Court the power to strike down laws that it finds to be unconstitutional
1857: Dred Scott v. Sandford ruled that African Americans are not citizens and have no rights under the Constitution.
1896: Plessy v. Ferguson upheld the constitutionality of racial segregation, establishing the separate but equal doctrine
1954: Brown v. Board of Education overturned Plessy v. Ferguson and declared that racial segregation in public schools is unconstitutional
1973: Roe v. Wade legalized abortion nationwide.
2015: Obergefell v. Hodges legalized same-sex marriage nationwide.