Julian Parks Boyd, 76 professor emeritus of history at Princeton University and editor of "The Papers of Thomas Jefferson," a work that has been widely noted for its scholarship as well as for its monumental nature, died Wednesday at the Medical Center at Princeton. He had cancer and heart ailments.

The first volume of "The Papers" was published in 1950. At the time of Prof. Boyd's death, the 20th volume was all but completed. In all, the series is expected to contain 60 volumes comprising more than 60,000 documents and about 23 million words as Prof. Boyd's work is carried on.

The project has been described as one of the largest publishing undertakings in the nation's history. Prof. Boyd's efforts are regarded as having set a new standard for collecting and publishing historical documents.

In addition to his work as an editor, Prof. Boyd was a historian who specialized in the 18th century, an author of numerous books, and a librarian. He was a former president of the American Historical Association and a president of the American Philosophical Society. The latter is the oldest learned society in the United States and counted Jefferson and other "founding fathers" among its members.

In 1976, Prof. Boyd took the initiative in raising funds for the purchase of Battle Abbey, the site of the Battle of Hastings in England, to preserve it from commercial development and to make a gift of it to the British nation. For this he was made an honorary Commander of the Order of the British Empire by Queen Elizabeth II.

The informing principle of Prof. Boyd's work on Thomas Jefferson was that the nation would forget Jefferson's words at its peril. The notion that "all men are created equal" and that they are "endowed by their Creator with certain inalienable rights, that among these are life, liberty, and the pursuit of happiness," remained for him a vital and guiding force.

Thus, speaking at the unveiling of a mural depicting the adoption of the Virginia Declaration of Rights in Richmond in 1951, he warned against the excesses of the anti-Communist feeling that was sweeping the country at that time.

"We have been seized in a mounting wave of hysteria," Prof. Boyd said. "Test oaths of increasing severity are being required of public servants, teachers, librarians and others, and are being proposed even as a condition precedent for those about to enter professions or trades. Books are being banned or suppressed not because they contravene laws, but because of the ideas they contain. In many other respects we are in danger of doing violence to the letter and the spirit of the Bill of Rights."

Prof. Boyd continued to enunciate these ideas for the rest of his life. In a review of Volumes 18 and 19 of "The Papers," Morrill D. Peterson, writing in "The William & Mary Quarterly," said, "Boyd's running commentary on the documents has the character of a moral drama involving the destiny of the American Revolution."

A native of Converse, S.C., Prof. Boyd graduated from Duke University in 1925 and earned a master's degree in history there a year later. uAlthough he was the recipient of numerous honorary doctorates, he never earned one himself. He was one of the few full faculty members at Princeton not to have done so.

He was an instructor at the University of Pennsylvania and then became editor of "The Susquehanna Company Papers" for the Wyoming Historical and Geological Society in Wilkes-Barre, Pa. In 1932, he was named director of the New York State Historical Association. In 1934, he returned to Pennsylvania as librarian and editor of the Historical Society of Pennsylvania.

In 1940, he went to Princeton University as its librarian.

He was Princeton's librarian for 12 years. During that time, he helped raise funds for and plan the Harvey S. Firestone Memorial Library there. In 1952, he became a full professor of history and remained in that position until 1972, when he was named professor emeritus. He continued to work on the Jefferson Papers at Princeton until his death.

The work on "The Papers" was begun in the 1940s with a grant from the New York Times Co. It has continued with additional grants from private organizations and from the National Historical Publications and Records Commission, a federal body. Prof. Boyd was a member of the commission from 1951 to 1964.

Prof. Boyd's books, in addition to "The Papers," include "Indian Treaties Printed by Benjamin Franklin." which he wrote with Carl Van Doren, "Anglo-American Union," "The Declaration of Independence: Evolution of the Text," and Number 7: Alexander Hamilton's Attempts to Control American Foreign Policy."

Survivors include his wife of 52 years, the former Grace Wiggins Welch, of Titusville, N.J., where the family lives; a son, Kenneth M., of Washington; a sister, Frances Flintom, of Charlotte, N.C., and a brother, Henry T., of Lake Wales, Fla.