… is from page 150 of the late Harvard and AEI economist Gottfried Haberler’s 1974 book, Economic Growth & Stability: An Analysis of Economic Change and Policies (footnote deleted; link added):
The broad fact is that in the [19th-century] United States the conditions for economic and industrial development were so favorable that tariff protection cannot have been more than a comparatively minor element in the whole picture. It surely has speeded up the growth of particular industries in certain locations, but the great sweep of overall growth was shaped by other more basic factors, especially the successive waves of immigrants from Europe, and was only marginally influenced, favorably or unfavorably, by tariff policies. These policies, it should be noted, have not been uniformly protectionist; periods of high protection alternated with periods of comparatively low duties. But whatever the overall impact of protection, which certainly was not profound and may well have been unfavorable both quantitatively (reducing the secular growth rate of GNP) and qualitatively (fostering the growth of urban slums), more important are the lessons taught by certain internal developments inside the U.S. economy.
[Frank] Taussig drew attention to the fact that inside the United States industrial centers sprang up, in the Middle West, later in the Far West and South, although these regions lacked tariff protection from the competition of the old established industries on the Atlantic Seaboard. This was contrary to what one would have expected on infant industry grounds.