Robert Todd Lincoln Beckwith (July 19, 1904 – December 24, 1985) was the great-grandson of Abraham Lincoln. In 1975, he became the last undisputed descendant of Lincoln when his sister, "Peggy" Beckwith, died without children. A disputed descendant, Timothy Lincoln Beckwith, was born to Robert Beckwith's then wife, Annemarie Hoffman Beckwith, in 1968.
Beckwith was born in Riverside, Illinois, to Jessie Harlan Lincoln and Warren Beckwith. As a young adult, he showed little interest in his schooling, attending a private school in Washington D.C. and New York Military Academy in New York, as well as passing two uneventful years at his grandfather Robert Todd Lincoln's previous boarding school, Phillips Exeter Academy. He did not attend college and tended to list his profession as "gentleman farmer of independent means". Financially set because of his inheritance, which included a farm, he left the farm's operation to its overseer, and aside from that ownership, there is no record of his ever having any form of employment.
Beckwith enjoyed the hobby of boating and sailing and generally avoided the media and publicity. On one occasion, a newspaper published pictures of him smiling as a young man when arrested for speeding in the city of Omaha, Nebraska.
Beckwith's first marriage, which lasted 30 years, was to an older widow whose son was only ten years his junior. His second wife had a son, named him Timothy Lincoln Beckwith, and listed Robert Beckwith as the boy's father. Robert Beckwith, however, was in the process of divorcing her, accusing her of adultery and denying paternity of the child, since he had a vasectomy years prior. During the divorce battle, the court ordered her to have her son undergo a blood test. She never complied with the order, and the divorce court ruled that Robert Beckwith was not the father.