John Adolphus Bernard Dahlgren, 56, who owned and operated a thoroughbred horse farm in Huntly, Va., with his daughter, Eva Elizabeth Dahlgren, died April 9 in a highway accident near his home.

Virginia State Police said Mr. Dahlgren was the driver of an automobile that went off the road and struck a tree on Rte. 522 in Rappahannock County. He was pronounced dead at the scene.

Mr. Dahlgren, a native of Philadelphia, was a graduate of the University of Virginia, where he was an All-America guard on the football team. He served in the Army during the Korea War.

He had lived in Huntly for more than 30 years. He was the owner and operator with his daughter of Windsor Lodge Farm and also was a real estate broker with Roy Wheeler Realty Inc. in Warrenton.

Mr. Dahlgren was master of foxhounds of the Rappahannock Hunt from 1979 to 1985 and was on the board of the Old Dominion Hounds.

He was a member of the Fauquier Club and the Society of the Cincinnati.

In addition to his daughter, survivors include his wife, Marjorie Morgenstierne Dahlgren, also of Huntly; a stepson, John Wilhelm Morgenstierne Coleman of Washington; two brothers, Joseph, of Santa Barbara, Calif., and Ulrich, of Annapolis, and a sister, Anne Hecht of New York City.