In 1954, James Nabrit and co-lead attorney George E.C. Hayes celebrated the outcome of Bolling v. Sharpe, DC's companion case to Brown v. Board of Education. For years, attorneys had argued in favor of equalizing white and black schools, but in Bolling and Brown, they successfully attacked segregation as inherently unequal. Because DC is not a state, and therefore not necessarily subject to the 14th Amendment, Nabrit and Hayes under Bolling led the Court to establish that the federal government had the same obligation as would a state government in guaranteeing its citizens equal protection.
Several years earlier, in Lane v. Wilson (1939), Nabrit successfully argued before the Supreme Court that a law preventing African Americans from ever being able to vote in the Oklahoma was unconstitutional. Nabrit also prevailed in 1955, when the Supreme Court ruled in Terry v. Adams that pre-primary elections limited to white voters violated the 15th Amendment. (NAACP attorney Thurgood Marshall had won a similar case, Smith v. Allright, a decade earlier, but a private, whites-only association had continued to exercise control over which candidates advanced to the Democratic primaries in Texas.)
Throughout his active career as a trial attorney, Nabrit served on the faculty at Howard University Law School; he is credited with teaching the first formal course in civil rights law beginning in 1938. The documentation he gathered for this course, on some two thousand civil rights-related cases from across the country, provided support for continued litigation by Nabrit and his colleagues throughout the 1930s-50s. Nabrit became Howard University's president in 1960. In a decade of increasing campus unrest, students sharply criticized his conservative leadership and staged a 5-day takeover of the Administration Building in 1968. He retired the following year.
During the 1940s, Nabrit lived at the Howard Manor at 654 Girard Street NW.