This document summarizes the evolution of equal protection law in the United States since the 1896 Plessy v. Ferguson decision established the "separate but equal" doctrine. It discusses how the Supreme Court gradually strengthened the "equal" component of Plessy through cases like Missouri ex rel. Gaines v. Canada (1938) and Sweatt v. Painter (1950). It then covers how Brown v. Board of Education (1954) overturned Plessy as it applied to public education. The document also outlines the three tiers of scrutiny—rational basis, intermediate, and strict scrutiny—that the Court has used to evaluate equal protection claims. It concludes by focusing on three important affirmative action cases from the 1970s.