who proclaimed that the western frontier was closed
Frontier Thesis Turner saw the land frontier was ending, since the U.S. Census of 1890 had officially stated that the American frontier had broken up. He sounded an alarming note, speculating as to what this meant for the continued dynamism of American society as the source of U.S. innovation and democratic ideals was disappearing.[citation needed]
War of 1812 American expansion into the Northwest Territory was being obstructed by various Indian tribes since the end of the Revolution, who were supplied and encouraged by the British. Americans on the western frontier demanded that interference be stopped.[42] There is dispute, however, over whether or not the American desire to annex Canada brought on the war. Several historians believe that the capture of Canada was intended only as a means to secure a bargaining chip, which would then be used to force Britain to back down on the maritime issues. It would also cut off food supplies for Britain's West Indian colonies, and temporarily prevent the British from continuing to arm the Indians.[43][44] However, many historians believe that a desire to annex Canada was a cause of the war. This view was more prevalent before 1940, but remains widely held today.[45][46][47][48][49][43] Congressman Richard Mentor Johnson told Congress that the constant Indian atrocities along the Wabash River in Indiana were enabled by supplies from Canada and were proof that "the war has already commenced.Â ... I shall never die contented until I see England's expulsion from North America and her territories incorporated into the United States."[50]