Former Harvard Corporation Fellow and famed presidential biographer John M. Blum ’43 died Oct. 17 from complications with pneumonia at his home in Branford, Conn. He was 90.

The longtime Yale history professor and holder of four Harvard degrees gained national recognition for his 1954 biography of Theodore Roosevelt, Class of 1880.

The biography, “The Republican Roosevelt,” helped redefine the former President’s legacy. In the book, Blum argued that Roosevelt had revitalized the presidency after years of institutional decline following the Civil War. Though popular opinion at the time of publication held Roosevelt as an average, if not whimsical leader, Blum’s scholarship established the 26th president’s reputation as a watershed figure.

Blum served as a Fellow of The Harvard Corporation—the University’s highest governing body—from 1970 to 1979, helping to lead the University through nearly a decade of change. At the time of his selection, Blum was the first professor to join the Corporation while actively teaching at another University.

One of Blum’s first tasks upon joining the Corporation was to help lead the search process for a new University president. The Corporation ultimately chose Derek C. Bok to replace outgoing president, Nathan M. Pusey ’28. Blum’s term also coincided with the merger of Radcliffe and Harvard in 1977.

“[Blum] had joined the Corporation just a couple of years before at a time when the University was beset by student protests. Together with another new member, Charles Slichter, he gave the Corporation a faculty presence and provided much insight and good advice about university affairs,” Bok wrote in an email.

Born in Manhattan on April 29, 1921, Blum was raised on Long Island and was the oldest of three children. Though his father was a businessman and inventor, Blum relied on scholarships and his own part-time jobs to pay his way through Phillips Academy and ultimately Harvard.

Blum graduated from Harvard College in 1943 and shortly thereafter joined the Navy, serving in the South Pacific for the remainder of World War II. After the war, he decided to return to Harvard, earning a master’s degree in 1947 and a Ph.D. in history in 1950. Harvard presented Blum with an honorary law degree in 1980, as well.

Blum’s professional career began in 1948 at M.I.T., where he taught for nine years before taking a position at Yale in 1957. Blum remained at Yale until his retirement in 1991, teaching some of Yale’s most famous political graduates, including George W. Bush and John F. Kerry. Harvard University Professor Henry Louis Gates Jr. was also a student and mentee of Blum.

“I learned a lot about writing from John Blum, and I learned a lot about history from John Blum. It was like the laying on of the hands,” Gates said in an National Endowment for the Humanities interview in 2002. Gates could not be reached for comment for this article.

Much of Blum’s most famous work was completed while at M.I.T. and in his early years at Yale. He wrote more than 15 books and contributed to various others, mostly concerning the American presidency. Blum helped popularize the study of presidential biography, tracing the personal traits and lives of presidents to their policy and leadership. His books included biographies on Woodrow Wilson, Franklin D. Roosevelt, Class of 1904, and Theodore Roosevelt, as well as detailed, multi-volume histories of the New Deal and World War II. Blum also authored an American history textbook and a memoir.

“His writings shaped historians’ understanding of Theodore Roosevelt, Franklin D. Roosevelt, and other figures in what was once the liberal mainstream of American public life,” wrote Harvard History Professor James T. Kloppenberg in an email. “A moderate who tried to mediate between radicals and conservatives at Yale, Blum remained resolutely, unapologetically focused on the centrality of politics in American history.”

Blum served as chair of the Yale History Department and was considered to be a top candidate for the position of president of the university. Though he never rose any higher than professor, Blum was an enormously influential figure on campus, and a favorite of students.

“I particularly remember him for his unfailing good humor and wise judgment and for his kindness to me as a new president in difficult times,” Bok said.

Notably, Blum—who was not a movie fan—made a cameo appearance in Woody Allen’s 1983 mock-documentary “Zelig,” playing a fictional historian with expertise on the documentary’s title character.

Blum is survived by his wife Pamela Zink Blum and three children. A memorial service will be held Nov. 11 at Yale’s Battell Chapel.

This article has been revised to reflect the following correction.

CORRECTION: OCT. 25, 2011

Due to an editing error, the Oct. 25 article "John Blum, Former Harvard Corporation Member, Dies at 90" incorrectly identified Franklin D. Roosevelt as a member of the Class of 2004. He was a member of the Class of 1904.