Brown, were the first historians to publish the American Revolutionary War journals of Henry Dearborn, in 1939, making them available to the general public for the first time.

[1] After graduating from Lowell High School, Peckham first attended Olivet College, then transferred to the University of Michigan just as the Great Depression began.

When Peckham was diagnosed with diabetes in mid career, Dorothy's culinary ability and vigilant eye minimized the effects on his daily routine and allowed him to perform throughout the remainder of his life.

[3] As an undergraduate, he worked as a student reporter for The Michigan Daily newspaper and began his association with the William Clements Library in 1929.

Returning to his home town of Lowell, Peckham began his literary career as an editorial writer for The Grand Rapids Press.

[2] Under his management, the library provided a rich environment of archival knowledge and education for students and scholars pursuing the study of early American history.

When the Great Depression came, however, William Clements suffered severe financial loss and subsequently made out his will, reluctantly asking that the university purchase the valuable collection of manuscripts.

[5] Peckham worked closely with Carl Van Doren on his Secret History of the American Revolution (1941), editing documents from the Clinton Papers that revealed Benedict Arnold's treason.

[2] He was the first person to unfold, sort, and read the most historically significant collection of Revolutionary War documents ever to come into the possession of an American library, about which Life did an exclusive story.

Peckham returned to Ann Arbor in 1953, shortly after the death of former director Randolph Adams, and was formally appointed Director of Clements Library, where he began greatly expanding the library's colonial and revolutionary collections, personally contributing many important manuscripts for the early American and antebellum periods.

[8] By the middle of the 1970s, Peckham and his wife decided for health reasons to move to a warmer climate in Hendersonville, North Carolina, where they lived a more relaxed lifestyle.

[3][10] At his retirement, Peckham expressed his great enthusiasm for the Clements library, claiming and truly believing that it was the best place anywhere to acquire manuscripts and other primary sources on early American history.

[12] It is said that Peckham is remembered by his colleagues and the many scholars who came to the Clements Library as graduate students, as a kind and giving man with a courteous manner.