Richard Helms later became Director of the CIA. His letter to Dennis now resides in their museum.
(This letter, and many other fascinating pieces of correspondence, can be found in the bestselling book, More Letters of Note. For more info, visit Books of Note.)

Transcript
OBERSALZBERG, DEN V-E day
ADOLF HITLER
Dear Dennis,
The man who might have written on this card once controlled Europe — three short years ago when you were born. Today he is dead, his memory despised, his country in ruins. He had a thirst for power, a low opinion of man as an individual, and a fear of intellectual honesty. He was a force for evil in the world. His passing, his defeat — a boon to mankind. But thousands died that it might be so. The price for ridding society of bad is always high.
Love, Daddy