Jack Greenberg was only 27 years old when he stood before the U.S. Supreme Court and helped argue one of the most important cases in U.S. history, Brown v. Board of Education . “We prepared and prepared and prepared, so I wasn’t nervous,” says Greenberg. “I didn’t doubt that we would win.”

Still, when the Court handed down its landmark decision in 1954, ruling that segregation in public schools was unconstitutional, Greenberg says that he, lead lawyer Thurgood Marshall, and the other attorneys who worked on the case “walked around stunned.”