President Lyndon B. Johnson appoints U.S. Court of Appeals Judge Thurgood Marshall to fill the seat of retiring Supreme Court Associate Justice Tom C. Clark. On August 30, after a heated debate, the Senate confirmed Marshall’s nomination by a vote of 69 to 11. Two days later, he was sworn in by Chief Justice Earl Warren, making him the first African American in history to sit on America’s highest court.

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The great-grandson of slaves, Marshall was born in Baltimore, Maryland, in 1908. In 1933, after studying under the tutelage of civil liberties lawyer Charles H. Houston, he received his law degree from Howard University in Washington, D.C. In 1936, he joined the legal division of the National Association for the Advancement of Colored People (NAACP), of which Houston was director, and two years later succeeded his mentor in the organization’s top legal post.

As the NAACP’s chief counsel from 1938 to 1961, he argued 32 cases before the U.S. Supreme Court, successfully challenging racial segregation, most notably in public education. He won 29 of these cases, including a groundbreaking victory in 1954’s Brown v. Board of Education, in which the Supreme Court ruled that segregation violated the 14th Amendment to the Constitution and was thus illegal. The decision served as a great impetus for the African American civil rights movement of the 1950s and 1960s and ultimately led to the abolishment of segregation in all public facilities and accommodations.

In 1961, President John F. Kennedy appointed Marshall to the U.S. Court of Appeals, but his nomination was opposed by many Southern senators, and he was not confirmed until the next year. In June 1967, President Johnson nominated him to the Supreme Court, and in late August he was confirmed. During his 24 years on the high court, Associate Justice Marshall consistently challenged discrimination based on race or sex, opposed the death penalty, and supported the rights of criminal defendants. He also defended affirmative action and women’s right to reproductive freedom. As appointments by a largely Republican White House changed the politics of the Court, Marshall found his liberal opinions increasingly in the minority. He retired in 1991, and two years later passed away.

READ MORE: Thurgood Marshall: His Life and Legacy