What did alger hiss, whittaker chambers and ethel rosenburg have in common

The thing that Alger Hiss, Hittaker Chambers and Ethel Rosenburg had in common is that all of them were subjects of espionage investigations that occurred as part of a Red Scare. These people were considered unloyal to America. Alger Hiss was proclaimed as a thief and Julis and Ethel Rosenberg were accused of commiting a espionage. So, in other words they all were treated like betrayers.

Very useful. it is to learn because history repeats itself so learning about it those mistakes not happen again.