Thurgood Marshall’s most famous civil rights cases form a deliberate chain of Supreme Court victories that dismantled legal segregation piece by piece, starting with voting rights and criminal procedure in the 1940s and ending with the destruction of “separate but equal” in public schools in 1954. As head of the NAACP Legal Defense and Educational Fund from 1940 onward, Marshall picked his targets carefully, winning narrow rulings in graduate school and primary election cases that built the precedent base for Brown v. Board of Education.1National Park Service. Thurgood Marshall: A Legacy of Civil Rights Leadership
Murray v. Pearson: The Maryland Template
Before Marshall reached the Supreme Court, he and his mentor Charles Hamilton Houston won a 1935 case in Maryland on behalf of Donald Gaines Murray, who had been rejected from the University of Maryland School of Law solely because he was Black.2Maryland State Archives. From Segregation to Integration: The Donald Murray Case, 1935-1937 Maryland had offered out-of-state tuition grants as a substitute. Marshall argued the state could not meet its obligations to Black residents by pointing to schools somewhere else.
A Baltimore circuit court ordered Murray admitted, and the Maryland Court of Appeals affirmed in January 1936. The case never reached the U.S. Supreme Court, so its binding effect was limited to Maryland. But it handed Marshall the strategy he would use for the next two decades: attack segregation in graduate and professional education first, where the inequality was easiest to prove and the political backlash smallest.
Chambers v. Florida (1940)
Marshall’s first major Supreme Court case was not about schools at all. Four young Black men had been convicted of murder in Florida after being held in isolation and interrogated repeatedly over several days with no lawyer present. Their confessions were the heart of the prosecution’s case.3Library of Congress. Chambers v. Florida, 309 U.S. 227 (1940)
Marshall argued that confessions pulled out of defendants through prolonged coercion violated the Due Process Clause of the Fourteenth Amendment. The Supreme Court agreed unanimously and reversed the convictions. The ruling held that the Constitution does not tolerate convictions built on forced admissions, and it signaled that Marshall’s work would not be confined to education. The protection of Black defendants in a hostile criminal system was part of the same project.
Smith v. Allwright (1944)
Texas Democrats ran what they called a “white primary,” restricting primary voting to white citizens. In a one-party state, the Democratic primary decided who held office; shutting Black voters out of the primary shut them out of government entirely.
Marshall represented Lonnie Smith, a Black voter from Harris County who had been refused a ballot in the 1940 Democratic primary.4Library of Congress. Smith v. Allwright The question was whether a political party’s internal rules counted as “state action” under the Fifteenth Amendment. Nine years earlier, in Grovey v. Townsend, the Court had treated party primaries as private affairs beyond federal reach.
The Court reversed itself. Justice Reed, writing for the majority, held that Texas had tied its primary elections so tightly into the state’s electoral machinery that the party’s racial exclusion amounted to state action and violated the Fifteenth Amendment.5Justia U.S. Supreme Court Center. Smith v. Allwright Grovey was explicitly overruled, and the legal foundation of the white primary across the South collapsed.
Shelley v. Kraemer (1948)
Racially restrictive covenants were private agreements among white property owners not to sell their homes to non-white buyers. They kept entire neighborhoods closed to Black families for decades. When the Shelleys, who were Black, bought a house in St. Louis, white neighbors sued to enforce such a covenant and remove them.
Marshall argued a companion case in the consolidated litigation. The central question was narrow but powerful: a private discriminatory agreement might be legal, but could a state court enforce one without becoming a party to the discrimination?6Library of Congress. Shelley v. Kraemer, 334 U.S. 1 (1948) The Supreme Court said no. The moment a judge orders a family out of a home because of race, the government becomes an active participant, and the Equal Protection Clause of the Fourteenth Amendment forbids it.7Justia U.S. Supreme Court Center. Shelley v. Kraemer, 334 U.S. 1 (1948)
The decision did not ban restrictive covenants. Neighbors remained free to sign them. Without court enforcement, though, they lost their power.
Sweatt v. Painter and McLaurin v. Oklahoma State Regents (1950)
Two cases decided the same day pushed “separate but equal” to its breaking point in graduate education.
Heman Marion Sweatt was denied admission to the University of Texas Law School because of his race. Texas tried to satisfy the Constitution by creating a separate law school for Black students, but the comparison was absurd. The University of Texas had sixteen full-time professors, 850 students, a 65,000-volume library, and generations of alumni. The new school had five professors, 23 students, and 16,500 volumes.8Justia U.S. Supreme Court Center. Sweatt v. Painter, 339 U.S. 629 (1950) Marshall pushed the Court past the physical count and into the intangibles: faculty reputation, alumni networks, prestige, and the professional relationships students build during their training. The Court unanimously ordered Sweatt admitted, holding that the separate school was not substantially equal.9Library of Congress. Sweatt v. Painter, 339 U.S. 629 (1950)
George McLaurin’s case attacked the other side of the problem. He had been admitted to a doctoral program in education at the University of Oklahoma by court order, but the university then forced him to sit in a separate section of the classroom, at a designated desk in the library, and at a different table in the cafeteria.1National Park Service. Thurgood Marshall: A Legacy of Civil Rights Leadership Marshall argued the restrictions impaired his ability to study, discuss, and learn his profession. A unanimous Court agreed. Admitting a student and then isolating him did not satisfy the Equal Protection Clause.
Neither ruling overturned Plessy v. Ferguson. Together they made clear that defending separate but equal was becoming impossible in practice.
Brown v. Board of Education (1954)
Two decades of groundwork converged in Brown v. Board of Education, which consolidated school segregation challenges from Kansas, South Carolina, Virginia, and Delaware.10National Archives. Brown v. Board of Education (1954) Marshall led the legal team and widened the argument beyond building comparisons. He presented psychological evidence that segregation itself produced a feeling of inferiority in Black children that damaged their motivation and development. The claim was that separate facilities are inherently unequal, regardless of spending.
On May 17, 1954, Chief Justice Earl Warren delivered the unanimous opinion. Segregation in public schools violated the Equal Protection Clause of the Fourteenth Amendment, and the “separate but equal” doctrine from Plessy v. Ferguson had no place in public education.10National Archives. Brown v. Board of Education (1954) Warren wrote that education was perhaps the most important function of state and local government and that denying equal access on the basis of race took something from children they could never recover.
The decision destroyed the constitutional foundation for state-sponsored school segregation. Enforcement was a separate problem. A year later, in what became known as Brown II, the Court instructed school districts to desegregate “with all deliberate speed,” language that gave local authorities room to move slowly and, in many places, to resist for years.10National Archives. Brown v. Board of Education (1954) The legal victory was complete even as the practical fight stretched across decades, and Brown remains the most consequential Supreme Court civil rights decision of the twentieth century.