Returning to the United States, Gipson taught at The College of Idaho for three years and, in 1909, married Jeannette Reed (who died in 1967).
He then attended Yale University as a Farnham Fellow from 1910 to 1911 before being named head of the history department at Wabash College, a position he held until 1924.
Although best known as a historian of Colonial America and its place in the British Empire, two of Gipson's earliest articles had to do with the Civil War and Reconstruction.
His thesis is succinctly presented in his article "The American Revolution as an Aftermath of the Great War for the Empire, 1754-1763," which was published in the March 1950 issue of Political Science Quarterly.
Gipson noted that he himself was a member of the Congregational Church and a descendant of the pilgrim William Brewster, while Hoffman was a convert to Roman Catholicism and a staunch defender of that faith - and yet they were good friends.