American historian best remembered for a monumental study of his country's development from AD 1000 through the American Civil War (1861–65).

Channing, a son of the poet William Ellery Channing (1817–1901), was associated throughout his career with Harvard University, where he taught from 1883 to 1929. Channing's outlook was influenced by social Darwinism, which led him to stress the forces of union over those of particularism as the dominant theme in U.S. history. Based on original sources, his research stressed the unique contribution of each section to the whole. In emphasizing the significance of urbanization and of improvements in transportation, he challenged the frontier thesis of his illustrious colleague Frederick Jackson Turner (Turner, Frederick Jackson). Although Channing was sometimes chided for his New England bias, his History of the United States, 6 vol. (1905–25), ranks as a major accomplishment in American historical writing. The sixth volume was awarded the Pulitzer Prize for History.