Middleton later stated that his own practices in physical examination of patients, teaching of medical students and house officers, and ethics were derived from those of Riesman.

[4] Middleton was invited to join the faculty at the University of Wisconsin (UW; in Madison, WI) - then a 2-year medical school - immediately after his internship.

[5] Middleton had broad interests regarding areas of clinical investigation, but they especially centered on sarcoidosis, pneumoconiosis, hematological disorders, infectious diseases and medical history.

[6][7][8][9][10][11][12][13] He steadily rose through the academic ranks, and when the medical school became a four-year degree-granting entity in 1924 and built a university hospital, Middleton emerged as a central figure in the education of third- and fourth-year clinical clerks as well as house officers in internal medicine.

[15][16] A novel and innovative program of "preceptorships" was initiated in 1926, wherein senior medical students were assigned to work with community practitioners throughout Wisconsin as a prelude to internship.

He continued to teach actively and to pursue his own research interests despite the administrative demands on his time, ultimately producing more than 300 contributions to the peer-reviewed medical literature.

[3] He was instrumental in formulating a national curriculum for residency training in internal medicine and a structured system of examination to achieve board-certification in that medical specialty.

He was awarded the Distinguished Service Medal, the Legion of Merit with Oak Leaf Cluster, the Croix de Guerre with Palm, and the Order of the British Empire.

[21] Programs for veterans that were developed during his tenure included improved access to physical rehabilitation services, mental health care, and treatment for cardiovascular diseases.