Flint was particularly interested in the Middle West. Therefore, after a brief sojourn in New York and Philadelphia, where he commented judiciously on all that made for the higher life of these two young cities, he followed the great Western thoroughfare which crossed Pennsylvania to Pittsburg, then the gateway of trans-Allegheny America. Here he purchased a skiff and floated down the Ohio, occasionally landing to make visits and observations; from Portsmouth he proceeded on a circuit through Ohio and Kentucky, settling at length at the falls of Ohio, in the Indiana town of Jeffersonville. A resident at this place for several months, his investigation of Western conditions assumed a new phase. No longer the passing traveller, noting the novelties and peculiarities of the people, Flint began a systematic observation of American institutions in general, and particularly the political, social, and economic life of the Middle West. In his succinct but comprehensive study of the national constitution and local state governments, he anticipates De Tocqueville and Bryce. His comments upon the judicial system show an appreciation of the stern necessities of primitive justice, coupled with the law-abiding spirit characteristic of the Anglo-Saxon race. His notes upon the power of public opinion as a restraining force in political life, and upon the universal veneration for the constitution, show that he discovered the fundamental principles underlying American political life. His comprehension of the historical development of the West is remarkable for keen insight and prophetic vision. He realized what the acquisition of Louisiana had meant in dispelling the dangers of a Western secession from the republic; and showed that the true interests of the West allied her with Eastern markets. Looming large on the horizon, Flint discerned the second factor which was to rend American life. The discussion of the Missouri Compromise had scarce begun, but already he saw that the nation could not always exist half-slave and half-free. He saw also that the long border line forming a kind of moral boundary, was the crucial difficulty, and that the acute stage in the controversy would be reached over the question of fugitive slaves. To the present generation these seem self-evident truths; but few Americans and fewer foreigners had the keenness to perceive this before 1820. Flint, however, unlike many Englishmen of his day, was no radical condemner of slavery; he appreciated its patriarchal features and its real benefits for the negroes. He also saw that the masters suffered more deterioration by the system than the slaves; that the responsibility for the system rested not upon present, but historic conditions; and that wholesale denunciation was not only unjust, but useless.