Hugo Black was known as a defender of civil rights during his three decades on the Supreme Court, but part of his life sits on the other side of the scales.

Born on this day in 1886, Hugo Lafayette Black, a lawyer and politician from Alabama, was appointed to the U.S. Supreme Court in 1937. Not long after, a reporter exposed his affiliation with notorious racist organization the Ku Klux Klan.

“Justice Black Revealed as Ku Klux Klansman,” reads the headline on the front page of the September 13, 1937 Pittsburgh Post-Gazette. Reporter Ray Sprigle’s investigation of Black’s links to the Klan revealed that he joined the organization in September 1923 and resigned almost two years later, in July 1925.

“His resignation, scrawled in longhand on a sheet of the stationery of the Grand Dragon of the Alabama Klan, was the first move of his campaign for the Democratic nomination for United States Senator from Alabama,” Sprigle wrote. But the reporter had also discovered that in September 1926, while he was still running for the Senate, Black was welcomed back into the Klan and given a life membership.

Public and political response to these allegations was overwhelmingly negative, writes Howard Ball in his book on Black. Politicians who had voted for his appointment to the Senate said they wouldn’t have done so if they had known back in 1925, and newspapers called him everything from a “vulgar dog” to a “coward.”

At issue wasn’t just the Klan’s acknowledged brutality and racism towards black people: anti-Catholic and anti-Jewish sentiment in the Klan got significantly more press at the time, Ball writes.

Sprigle won a Pulitzer Prize for uncovering Black’s Klan links. But the story was complicated by the Supreme Court member’s progressive allegiances with FDR and the New Deal. Black himself believed he was being attacked as part of a war on FDR and his policies, Ball writes.

“They brought out no new facts that have not been thoroughly brought out in campaigns in Alabama,” Black wrote in a letter to an acquaintance in late October 1937. “With their practically united press, however (which is chiefly against the President), they had no difficulty in making the public believe that they had broken a startling piece of news.” At a press conference, though, FDR maintained he and the public hadn’t been aware of Black’s links to the Klan.

And Black certainly went to some effort to distance himself from the Klan during a radio speech he gave on October 1. In that speech he directly talked about Sprigle’s story, saying:

I did join the Klan. I later resigned. I never rejoined. What appeared then, or what appears now, on the records of that organization I do not know. I never have considered and I do not now consider the unsolicited card given to me shortly after my nomination to the Senate [in 1926] as a membership of any kind in the Ku Klux Klan. I never used it. I did not even keep it. Before becoming a Senator I dropped the Klan. I have had nothing to do with it since that time.

Some historical records indicate that Roosevelt did know about Black’s association with the KKK, Ball writes. But in terms of the public record, the matter rested there until Black's death, a week after he retired from the Supreme Court after 34 years. In the course of that career, he made his mark “as a champion of civil rights and liberties,” the New York Times wrote in his obituary.

That obituary suggested that Sprigle’s interpretation of the evidence he found was incorrect and that the story had been leaked by the Klan to discredit the liberal Black. It also revealed an interview that Black had given the Times in 1967 with the intent of setting the record straight, on the agreement that it wouldn’t be published until after his death.

In that interview, Black said he joined because he wanted to keep the organization from getting too extreme and because many other Alabama lawyers belonged to it. He maintained that he he was against hate and that the Klan he joined was “a fraternal organization, really.”