In 1949, Potomac School played a role in the famous trial of alleged Soviet spy Alger Hiss.  Priscilla Hiss was a teacher at the school in the late 1930s, when her husband worked in the State Department.  At the trial, the government alleged that Priscilla Hiss used the family’s typewriter to copy secret documents that Alger Hiss had stolen from the State Department.  Prosecutors introduced expert testimony to show that an application for admission to Potomac School, typed by Alger Hiss for his stepson, was produced on the same typewriter as government documents that he allegedly provided to Whittaker Chambers.  When the FBI visited Potomac to request access to correspondence relating to the Hiss family, the school’s headmistress initially refused, saying that even if Alger Hiss told her that he was a Soviet spy, she wouldn’t believe him.