The hospital board bought property on Kingshighway, just two blocks from Barnes Hospital and St. Louis Children's Hospital, to build a facility that would meet the ever-increasing need for expansion.
When it opened in 1927, the new hospital was hailed for its elegant design and functional innovations, winning the Modern Hospital of the Year award from the American Hospital Association. Its notable features included an audible nurse call system with speakers in each patient room, open-air balconies for treating patients with tuberculosis and state-of-the-art operating rooms.
Staff members from Barnes Hospital, St. Louis Children's Hospital and Washington University school of Medicine formed a medical hospital that served in France during World War I. While in France, Dr. Vilray P. Blair was helping to develop a new surgical discipline: plastic surgery.
In 1919, Dr. Evarts A. Graham became surgeon-in-chief. Throughout his long career, he helped establish the discipline of chest surgery. His innovations included in 1925 developing a method to image the gallbladder by x-ray, paving the way for successful gallbladder surgery. He also was the first surgeon to remove an entire lung successfully.
In the 1920s, Barnes was one of the first hospitals in the country to treat diabetic patients with insulin, and received a gift of $10,000 from John D. Rockefeller to fund the treatment.