Marion Moncure Duncan, 64, former president general of the Daughters of the American Revolution, who was active also in civic organizations, died of cancer April 15 at Circle Terrace Hospital in Alexandria.

She was the first Virginian to head the National Society of the DAR, serving during 1962-65. She also was president of the Order of the First Families of Virginia until resigning two month s ago because of ill health.

Mrs. Duncan had been appointed to a number of public service positions in Virginia. She also was well known in the Alexandria business community where she headed the insurance.

Born in Alexandria, the daughter of Judge Robinson Moncure and Ida Grigg Moncure, Mrs, Duncan was eligible for DAR membership through a number of family lines. She chose the Washington line. At the age of 18, she became the youngest charter member of the John Alexander chapter of the DAR in Alexandria. That was in 1932.

She moved on to become Virginia stato regent in 1950. When she was elected President general of the DAR in 1962, she was the youngest to hold that position.

Mrs. Duncan had based her campaign on a pledge to interest more young people in the DAR and to enlist them as active members. During her three-year term, the society made outstanding progress on that front.

She considered her administration's most significant "legacy" to the society to be publication of "In Washington . . . The and DAR history.

Mrs. Duncan often had stressed that she wanted to create a better punlic image of the historic patriotic soceity, because too little of its "good works had been told to the public, while its mistakes and negative actions had made headlines.

She cited the schools maintained by the DAR in remote schools mountain areas of the South and emphasized the historic and patriotic princiles of the society and the worth of its museum at Constitution Hall.

Mrs. Duncan also had been active in the Soceity of the Doughters of the Barons of Runnymede, the Colonial Daughters of the 17th Century and the Daughters of Colonial Wars.

In 1963, she served on the distinguished awards jury of the Freedoms Foundation and the next year received its George Washington Medallion Award. She also was a trustee of the produced the outdoor pagent, "The Common Glory," in Virginia.

Mrs. Duncan had attended the Colledge of William and Mary and later George Washington University. In 1966, she was appointed by the Virginia governor to the first of two terms on William and Mary's board of visitors. She was one of the Foundation for Independent Junior Colleges in Virginia.

She was involved in amny Bicential activities, either as a member of or an adviser to the Alexandria Becentennial Commision and groups representing national patriotic organizations.

Mrs. Duncan became an insurance broker in 1950, and three years later became head of the insurance department of the firm operated by her husband, Robert V!H! Duncan. She retired two years ago.

She was a member of the Virginia Association of Insurance Agents, Zonta INternational and the International Platform Association.

She was the co-author of a 40-generation genealogical volume, "House of Moncure."

In addition to her husband, of the home in Alexandria, she is survived by three sons, Robinson, of Leesburg, and Moncure and Bruce, both of Alexandria; a brother, Thomas Moncure, and a sister, Mrs. Clyde C. Lamond , also of Alexandria, and four grandchildren.