According to McCullough, between 1830 and 1860, nearly 700 American students came to Paris to study medicine. And most of these would have come from wealthy, influential families -- thus, many of not most would have been leaders in the American medical field.
It was said of Mason Warren -- "Apart from all other considerations, the mere fact that of his long absence in Europe caused a degree of importance to be attached to him, as in those days few of our countrymen traveled abroad..."
McCullough writes: "Decades later, in the 1890's, William Osler, one of the founders of the John Hopkins Medical School and as respected a figure as any in American medicine, would write that 'modern scientific medicine' had had 'its rise in France in the early days of this century.' More than any others, it was the pupils of Pierre Louis who gave 'impetus' to the scientific study of medicine in the United States."
Seventy of those who had trained in Paris, one out of three, taught in American medical schools.
-- William Gibson became chief of surgery at University of Pennsylvania.
-- Henry Williams became the first professor of ophthalmology at Harvard. He later wrote three important books on diseases of the eyes.
-- George Shattuck became dean of Harvard Medical School.
-- Henry Bowditch became professor of clinical medicine at Harvard. He was an expert in diseases of the chest, especially T.B. He published a book, The Young Stethoscopist, in 1846, used by medical students until the early 20th century.