Vernon Louis Parrington
Ed. and Introduction, The Connecticut Wits, 1926.
Main Currents in American Thought — Vol. 1, The Colonial Mind, 1620-1800 and Vol. 2, The Romantic Revolution in America, 1800-1860, 1927.
Sinclair Lewis: Our Own Diogenes, 1927.
Introduction to Giants in the Earth, O.E. Rölvaag, 1929.
Main Currents in American Thought — Vol. 3, The Beginnings of Critical Realism in America, 1860-1920, 1930.
Main Currents in American Thought (three volumes in one), 1930.