The woman who read Hank Aaron’s hate mail: In 1973, the baseball legend got 900,000 letters. It was Carla Koplin Cohn’s job to report the threats to the FBI.

On June 13th, 1974, two months after becoming baseball’s home run king, Henry Aaron received a plaque from the U.S. Postmaster General. It said “America’s #1.” In home runs and in fan mail.

Not all of it was from well-wishers. The 900,000 letters Aaron received in 1973 contained hundreds upon hundreds of racist attacks and death threats. Aaron, who died on Friday at age 86, was Black; the man whose record he’d broken, Babe Ruth, was white. Aaron ended the ’73 season one short of Ruth’s sacred 714 mark, and spent the winter worried he’d be assassinated before 1974’s opening day.