What is the trail of Alger Hiss?

What is the trail of Alger Hiss?

One of the trials which had great influence at that time was the trial of Alger Hiss. Hiss was an official of high position in the State Department. He was accused of being a Soviet spy. Later he was declared guilty of making false statements in court.（Only in recent years, was Hiss’s name cleared.）
Then it was disclosed that some scientists, who were Soviet spies, had passed on to the Soviet Union top secrets about the making of the atomic bomb.