I heard something similar from my late teacher Morton Frisch years ago, with an even shorter chain of acquaintanceship than Rick Brookhiser reports. I heard it that when Oliver Wendell Holmes, Jr. was a boy, he met an aged John Quincy Adams. (This should be somewhere in some biography of Holmes, surely.) That would make it just three lifetimes from the Revolution to the death of Hiss. As Professor Frisch remarked, it was a story of decline, Adams to Holmes to Hiss.