Curti attended high school in Omaha then obtained a bachelor's degree in 1920 from Harvard University, graduating summa cum laude.
Its chapters show an encyclopedic knowledge of thinkers great and small from the colonial period to the present, together with his commitment to democracy as a process springing from the ideas of the people.
Unlike Perry Miller at Harvard, who strongly influenced a new generation of intellectual historians, Curti never delved too deeply into the internal history of ideas, preferring to link them to multiple external social and economic factors.
In the 1950s Curti undertook a collaborative social history of rural Trempealeau County, Wisconsin using avant-garde quantitative analysis of census records.
The book which came out of the project, The Making of an American Community: A Case Study of Democracy in a Frontier County (1959) immediately became a pioneer work in what would soon be dubbed the "new social history."
In 1942, Curti was called to the Frederick Jackson Turner Professorship of History at the University of Wisconsin, one of the nation's most influential centers of historical scholarship; he retired from the department in 1968.
The Wisconsin department of history was notorious for the angry feuds among the senior professors, which Curti, mild-mannered and small of stature, completely ignored.
[citation needed] Curti supervised 86 finished doctoral dissertations at Columbia and Wisconsin, including many who became well-known scholars: Richard Hofstadter on social Darwinism; John Higham on nativism; Bourke on community studies; Allen Davis on Progressivism and Jane Addams; and Roderick Nash on the environment.
He encouraged his students constantly, wrote highly detailed critiques of their chapters, protected them from intradepartmental feuds, helped them get funding, and found them jobs through the "old boys" network of which he was an accomplished maestro, writing hundreds of letters a month to friends and ex-students across the globe.
In 1977 the Organization of American Historians established the Merle Curti Award, which is given annually for the best book in social, intellectual, and/or cultural history.