Although Marshall has a strong claim to being King’s equal as a civil-rights leader, his reputation could use a little polish. Marshall spent the last 24 years of his career on the Supreme Court, and while he certainly earned the job, it did not suit him. The Court’s cloistered halls muffled his belly-laughs-and-backslaps personality. His leading biographer, Juan Williams, devotes only 54 pages of his 400-page book to Marshall’s unhappy years in chambers, and those are not flattering. Studies of the Court in the 1970s and ’80s reveal an embittered man cut off from the outside world and dispirited by the ascendant conservatism of the Burger and Rehnquist Courts. Marshall was not effective in building coalitions with conservative justices—he wrote more dissents than majority opinions. He developed an unnerving habit of baiting his colleagues in a slave-boy dialect. During Elena Kagan’s confirmation hearings, in 2010, conservatives treated her prestigious clerkship for Marshall as a stain on her résumé.

The journalist Wil Haygood rehabilitates Marshall with Showdown, a book about one of the overlooked episodes of his career: the battle over his confirmation as the first African American nominee to the Court, in the summer of 1967, two years after he’d been appointed solicitor general. In coming to Marshall’s defense, Haygood joins Michael Long, the editor of a collection of Marshall’s early letters, a volume that begins with a forceful introductory essay equating Marshall with King. Haygood’s decision to focus on this turning point in Marshall’s life proves ingenious. Rather than discussing Marshall’s service on the Court in detail, he focuses on the gifts and accomplishments that got him there. He highlights two in particular. Marshall could display dignity and restraint in the face of unbearable provocation. He could also roar.

Lyndon B. Johnson nominated Marshall to the Court after engineering a vacancy: He appointed Justice Tom Clark’s son Ramsey as U.S. attorney general, creating a conflict of interest that prompted the justice to retire. Haygood overstates the case in saying that Johnson opened up the seat specifically for Marshall, but the president and his solicitor general enjoyed each other’s company. Williams writes, “The two men loved to drink bourbon and tell stories full of lies.” Once nominated, Marshall faced a group of nasty characters in the Senate. The chairman of the Judiciary Committee, James Eastland of Mississippi, was a notorious racist whose father had famously lynched a black couple. Eastland himself owned a plantation that employed more than 100 black sharecroppers. His daughter had been crowned Miss Confederacy 1956.

Other old bulls on the committee included John McClellan, Sam Ervin, and Strom Thurmond, a proud bigot who sired a child with a black maid and then paid hush money to his biracial daughter for years. During a notorious cross-examination, Thurmond brought Jim Crow into the hearing room by subjecting Marshall to nothing less than a literacy test, shrilly posing arcane questions (for instance, who were the members of the congressional committee that reviewed the Fourteenth Amendment in 1866?). Marshall kept his temper and repeatedly answered, “I don’t know, sir.” Later, Ted Kennedy asked Thurmond whether he could name the committee members. He couldn’t.