Farrand taught at Wesleyan University, then after several years at Stanford University, and a year at Cornell University, he became a professor of history at Yale University (1908–1925). His particular area of interest and expertise was the Founding Fathers, the organization of the United States after the American Revolutionary War. Farrand was also director of the Commonwealth Fund, founded in 1918 by Anna M. Harkness, widow of Stephen V. Harkness investor in Standard Oil, who wanted to “do something for the welfare of mankind.”
Max Farrand also assisted philanthropist Henry E. Huntington to establish the Huntington Library, which is located on the historic 'Rancho Huerta de Cuati' in San Marino near Pasadena, California. After Huntington's death in 1927, Farrand became the library's first director, serving until 1941.
Professor Farrand made many contributions to historical publications during his lifetime, as well as wrote the following books:
In 1913, while chairman of the history department at Yale University, Farrand married the renowned landscape architect Beatrix Farrand, the niece of the novelist and socialite Edith Wharton. They remodeled her family's home, Reef Point Estate in Bar Harbor on Mount Desert Island in Maine, where they spent summers while Farrand held positions in California and lived in Montecito near Santa Barbara, California. They had no children. His brother was the researcher Livingston Farrand.
The Farrands retired to Reef Point estate in Bar Harbor, which they planned to establish as an independent and self-perpetuating educational corporation. Max Farrand died there in 1945 and Beatrix Farrand established the foundation as they had planned. However, she came to realize in 1955, after a wildfire destroyed part of those gardens, that their plan for the foundation was impractical. She demolished the main house and uprooted the garden (John D. Rockefeller purchasing the azaleas for his own Asticou Azalea Garden in Northeast Harbor, Maine where they continue to flower), donated their extensive library and herbarium specimens to the University of California at Berkeley where researchers could more readily access it than in Maine, and lived the final three years of her life at Garland Farm nearby.
The Farrands are buried at Woodlawn Cemetery in New York City.
During the Bicentennial Celebrations, James Hutson, head of the Manuscripts Division of the Library of Congress, edited a revised edition of Farrand's four volume, The Records of the Federal Convention of 1787 (Yale University Press, 1976).