What was partly responsible for the trials of alger hiss and the rosenbergs?

The Second Red Scare was responsible for the trials of Alger Hiss and the Rosenbergs.

Explanation:

The Second Red Scare (also meaning: the phobia or concern for the infiltration of Communism) was what led to the trials of Alger Hiss, and Julius Rosenberg and Ethel Rosenberg (who were both referred to as "the Rosenbergs") : due to the fear that Communism was infiltrating, and seeking for sensitive information in the United States, the federal government focused its attention on Alger Hiss who was found to be an undercover agent for Communist Soviet Union, and the Rosenbergs who were found to have been passing information about the atomic bomb to the Kremlin. Alger Hiss and the Rosenbergs were tried after evidence was found against their activities.