. . .sets forth in the clearest possible manner the view of American expansion which has inspired and illuminated all of Professor Turner's work from the beginning. Among all American historians no one has so fully caught the meaning of the frontier in our national development.
—American Review of Books
Makes an excellent general presentation of a subject which is insufficiently understood by the average American, yet is so fascinating that any reader will be thankful to have it brought to his attention.
—Springfield Republican