"The Significance of the Frontier in American History" was the title of a speech delivered by Frederick Jackson Turner (1861–1932) in 1893 at the American Historical Association. Turner's thesis was that the presence of the frontier had had an enormous impact on the history of the nation and the character of its people: "to the frontier [that] the American intellect owes its striking characteristics."

Not all subsequent historians have accepted or celebrated Turner's thesis, however. For example, Howard Zinn does not even mention Frederick Jackson Turner by name in his A People's History of the United States. Zinn writes that two important events occurred in 1890: "The year of the massacre at Wounded Knee, 1890, it was officially declared by the Bureau of the Census that the internal frontier was closed." Zinn admits that the frontier ended by mentioning a crime that accompanied its demise. Moreover, he writes that the end of the frontier led to American colonization overseas.

Most historians today readily admit that Turner erred by downplaying the role of Indians, Asians, and African Americans in the country's history. Indeed, Turner's view was somewhat of an oversimplification. But his frontier thesis is still important today among American historians.

Frederick Jackson Turner's "Frontier Thesis" has had a major impact on historical thought since it was presented in 1893. At the time Turner presented his idea (it was eventually associated directly with his name and became the "Turner Thesis"), the American frontier was actually viewed as something that was disappearing. Turner argued that the constantly moving frontier was a key factor in the development of a unique American character and contributed to many of its essential features—egalitarianism, a certain down-to-earth anti-intellectualism, and even aspects of the society marked by conflict and violence.

In the events of the late nineteenth century that led up to Turner's thesis, one can certainly see expressions of the latter, as "manifest destiny" and western expansion were made possible through the use of violence, often directed at the indigenous populations living in the American West. Turner saw this as inevitable and part of the upward moving thrust of American society created by the dynamic frontier.

American historians have continued to be fascinated by Turner's thesis, and it has had significant academic influence. It has also been applied to other societies in other times—and even to American society more recently. One thinks here of the quest to land a man on the moon and the space race as a high-tech expression of the continuing challenge of the frontier and its stimulating impact on American society.

Frederick Jackson Turner presented an essay entitled, “The Significance of the Frontier in American History” in 1893 at the Chicago World’s Fair. He argued that all the characteristics that the world associated with the American national character were forged on the western frontier, and that it was the west, not the east, that truly dictated the course of American history. He went on to say that as pioneers went west, they abandon European practices in favor of self-discovered methods developed on the frontier.

His ideas were an instant hit. They were devoured by academics and debated in most major universities, but they also alarmed many people as well. With the 1890 census declaring he American Frontier closed, it was clear that a new chapter in our history was beginning. Many people continued his work by looking towards the possibilities of further colonization in the Pacific, but Turner’s work didn’t mention anything like this, instead concentrating on republicanism rather than territorial acquisition.