Creighton was heavily influenced by Harold Innis and took an economic approach to Canadian History. His main contribution was the development of the Laurentian Thesis, which described the basis of Canadian history by looking at the geography and the nation's dependence on the major centres. His two most important works are The Commercial Empire of the St. Lawrence (1937) and his two volume biography of John A. Macdonald.
In later years Creighton turned to expressing himself in the media. An intensive Canadian nationalist his opinions have often been criticized, especially his anti-Quebec views. His last book, The Forked Road: Canada, 1939-1957, is a clear example of how out-of-touch he became in later years. He died of cancer in Collingwood, Ontario in 1979.
Creighton was regarded by many as the foremost historian of his day and his influence is still strongly felt. Many of Canada's top historians studied under Creighton, such as Ramsay Cook and Michael Bliss, and Creighton's view of Canadian history is still often studied.
Creighton often engaged in feuds with historians whose interpretations he disliked, but he was well-known as a kind-hearted and munificent professor towards his students, albeit one who was severe with those who engaged in work that Creighton thought was wrong-headed.
Creighton detested the Liberal Party as he saw the Liberals as the party of continentalism (i.e moving Canada closer to the United States) and for taking steps that Creighton saw as an attack on Canada's British heritage, such as replacing the Red Ensign with the Maple Leaf flag in 1965.
Creighton's determination to maintain British traditions, his close association with Diefenbaker, and his dislike of continentalism led him to be accused of anti-Americanism.
The Infectious Diseases Fellowship is a two-year postgraduate training program in the Division of Infectious Diseases of Creighton University Department of Medical Microbiology and Department of Medicine along with the Infectious Diseases Division from the University of Nebraska Medical Center.
This facility was constructed in 1948 with a modern Ambulatory Care Facility added in 1987 and serves as a regional referral for veteran patients in western Iowa and the entire state of Nebraska.
The diagnostic microbiology laboratory is under the direction of Donald Giger, Ph.D., Assistant Professor of Medical Microbiology, Creighton University School of Medicine.