On April 20, 1971, the U.S. Supreme Court unanimously declares busing for the purposes of desegregation to be constitutional. The decision in Swann v. Charlotte-Mecklenburg Board of Education settled the constitutional question and allowed the widespread implementation of busing, which remained controversial over the next decade.

The Supreme Court’s 1954 ruling in Brown v. Board of Education officially banned racial segregation in American schools, but the end of formal segregation did not lead to a new era of total integration. Many previously segregated schools in the South remained desegregated in name only throughout the '50s and '60s, and the de facto segregation of neighborhoods across the nation meant that many technically-desegregated school districts had little or no racial diversity. Many city governments closed certain schools that were liable to become racially mixed and built new ones in more homogenous areas, creating new schools that were effectively segregated in order to avoid integrating old ones. Additionally, the “white flight” phenomenon saw many white families leave the cities for less-diverse suburbs, or move their children from integrated public schools to all-white private or parochial schools.

Thus, ten years after Brown, fewer than 5 percent of Black children in North Carolina’s Charlotte-Mecklenburg School District attended integrated schools. The city government’s solution was busing, the practice of intentionally moving children to schools outside of their school districts in order to desegregate. When the NAACP sued Charlotte on behalf of a six-year-old boy, James Swann, Judge James McMillan ruled in their favor, upholding the constitutionality of busing and ordering the city to begin moving students from inner-city Charlotte to schools in suburban Mecklenburg, and vice-versa. White parents were incensed, sending McMillan death threats, burning him in effigy, and forming the Concerned Parents Association, which launched an unsuccessful boycott of the public school system and ran a slate of anti-busing candidates for local office.

The case was appealed to the Supreme Court, which unanimously sided with the NAACP on April 20, 1971. The ruling allowed cities across the country to adopt busing, although a 1974 ruling restricted busing to districts that could be proven to have enacted discriminatory policies. From the Deep South to Boston to California, busing policies led to pushback and sometimes violence from white parents, and while many localities did achieve the goal of racial integration, the legacy of busing is still a controversial topic. By the end of the 20th century, busing had all but vanished thanks to legal challenges and local governmental decisions. Although critics argue that busing was unfair to all involved, placing a burden on the Black children it was meant to help, a study by the Civil Rights Project at Harvard University conducted in the early 2000s found that desegregation in American schools had regressed back to the same levels as the mid-'60s, and that the integration of public schools had peaked in 1988.