He was a Progressive Era intellectual who stressed material causes (such as economic profit and conflict between businessmen and farmers) and downplayed ideology and values as motivations for historical actors.

He was highly influential as a director of PhD dissertations at Harvard for three decades, especially in the fields of social, women's, and immigration history.

[5] In Boston in 1929, city officials, under the leadership of James Curley, threatened to arrest Margaret Sanger if she spoke on birth control.

His two sisters, Olga and Marion Etna, became schoolteachers and made it possible for their three younger brothers (George, Arthur, and Hugo) to attend college graduating in engineering, history and law.

He was a Progressive Era intellectual who stressed material causes (like economic profit) and downplayed ideology and values as motivations for historical actors.

He was highly influential as a director of PhD dissertations at Harvard for three decades, especially in the fields of social, women's, and immigration history.

[11] In "Tides of American Politics," a provocative essay in the Yale Review in 1939, he presented his cyclical view of history which identified irregular oscillations between liberal and conservative national moods, but it attracted few historians apart from his son.

In an essay on "The Significance of Jacksonian Democracy" (in New Viewpoints in American History (1922)), Schlesinger drew attention to the fact that "while democracy was working out its destiny in the forests of the Mississippi Valley, the men left behind in the eastern cities were engaging in a struggle to establish conditions of equality and social well-being adapted to their special circumstances."