The founding of the University of Texas M.D. Anderson Cancer Hospital in 1941 and the establishment of the Texas Medical Center in 1945 in large, part by the efforts of the M.D. Anderson Foundation are described. Dr. R. Lee Clark was appointed the first permanent Director of the MDAH in 1946 with the task of hiring the staff and getting the institution off the ground. In 1947, Dr. Gilbert Fletcher, an American, who had been born and raised in France told Clark he wanted to specialize in radiation treatments for cancer and was appointed a traveling fellow and sent to Europe to learn the latest advancements in cancer treatment. The information that he obtained about the prospects of radioactive isotopes in cancer treatment convinced Clark to make this an emphasis of the new hospital and to establish an “Atomic Center”. Fletcher met Grimmett in London who had been thinking about replacing radium with the new radioactive cobalt-60 in a radium treatment machine he had designed. Upon his return, Fletcher was appointed chairman of radiology at MDAH and recruited Grimmett to join him as the physicist at the hospital.