In June 1923 Walter Freeman arrived in Paris to work at the Salpêtrière under the patronage of the famed neurologist Pierre Marie. Freeman's grandfather, the distinguished surgeon William W. Keen, had written to Pierre Marie on Freeman's behalf, enabling the young medical graduate to study the classic neurology of the Salpêtrière, headed by Charcot's student and successor.

Many American medical students and young physicians trained in Europe. Paris was the primary destination until the mid-nineteenth century, known as the “French period” in American medicine. In the late nineteenth and early twentieth centuries, German medicine became preeminent, eclipsing the popularity of France. A number of studies on the “French impulse” in nineteenth-century medicine have been undertaken, yet little has been written on the training of young American physicians in France during the early twentieth century. At that time, there was a significant decline in the number of Americans studying in France. Young American physicians chose other European destinations or stayed in their home country, as the American medical education matured and offered local training opportunities. Still, many American physicians continued to obtain medical training in France, implementing their newly acquired knowledge and skills within the twentieth-century American medical setting. Following his return to the United States, the carbon copies of letters typewritten by Freeman to his family, friends, and colleagues, a number of letters from family and friends, as well as his sketches and scientific papers, were bound together, with a preface and an index added by Freeman.