The bloodline of Abraham Lincoln ended on Christmas Eve when his last direct descendant, Robert Todd Lincoln Beckwith, died in Hartfield, Va. at the age of 81.

Beckwith was Lincoln`s great-grandson. Although he married three times, he died childless, ending the 16th president`s family line.

The longtime owner of a farm in Middlesex County, Va., Beckwith was living in a Hartfield nursing home, according to the Bristow-Faulkner Funeral Home in Saluda, Va. Funeral arrangements were pending the arrival in Saluda of Beckwith`s wife, Margaret.

Abraham Lincoln and his wife, Mary Todd, had four sons. Only the eldest, Robert Todd Lincoln, lived to be an adult. He served as Secretary of War under Presidents James A. Garfield and Chester A. Arthur and died in 1926 at the age of 82.

Robert Todd Lincoln and his wife, Mary, had three children. Their youngest, Jessie, eloped in 1897 with Warren Beckwith, a classmate and football star at Iowa Wesleyan College.

The Beckwiths had two children, Mary Lincoln Beckwith, who died in 1975, and Robert Todd Lincoln Beckwith, who was born in suburban Riverside on July 19, 1904.

The Lincoln family name ended in 1926 with the death of Robert Todd Lincoln.

Beckwith was a short, fragile-looking man who bore little resemblance to his famed ancestor. He did not publicize his background, and once said he was occasionally embarrassed by the public`s fascination with his family history. Although he lived for several years with his grandfather, the result of his mother`s three marriages, he did not ask Robert Todd Lincoln about life in the White House.

''I was not especially interested,'' Beckwith told The Tribune in 1967.

But he kept at his Virginia farm several mementos of the Lincoln White House, including some pieces of the state china service--Haviland made in Limoges, France, with an American eagle in the center--and some of the Lincoln silver.

He also had Lincoln`s rifle, which he never shot. He later gave it to the Smithsonian Institution.

Beckwith left the Chicago area as an infant and lived most of his life in the Washington, D.C. vicinity. He received a law degree from what is now Georgetown University.

He helped represent Illinois at a special Illinois Day ceremony in 1964 at the New York World`s Fair, and was a guest of honor in a 1965 ceremony held in the City Hall council chamber here commemorating the 100th anniversary of Abraham Lincoln`s funeral in Chicago.

In 1976, Beckwith presented $100,000 worth of Lincoln memorabilia to Gov. Dan Walker for display in the Executive Mansion and the Illinois State Historical Library.

Among the gifts was a portrait of Mary Todd Lincoln that she had commissioned as a surprise gift for her husband. He was assassinated before she could present it. Mrs. Lincoln wanted the painting destroyed, but the artist saved it, and it eventually reached Beckwith.