Samuel Albert Levine was a key figure in modern cardiology in the United States. During the first world war he was one of a select group of United States medical officers assigned to the British Military Heart Hospital where he encountered the "British medical giants"--Clifford Allbutt, William Osler, James Mackenzie, and Thomas Lewis. Levine's diary, written when he was a young medical officer during the first world war, presents crisp character sketches of James Mackenzie and Thomas Lewis. The autobiographical vignettes he wrote later in life were more gracious and polished retrospectives. The Levine perspectives, separated by a half century, contribute to our understanding of the developing fabric of Anglo-American cardiology.