Beeckman was married first to Eleanor Thomas of Zanesville, Ohio in 1902.
 She was the daughter of Gen. Samuel Russell Thomas and Ann Augusta (née Porter) Thomas and the sister of Edward Russell Thomas.
 Upon her father's death in 1903, she inherited the income from half of his $10,000,000 estate.

After his first wife's death in 1920, he remarried Edna (née Marston) Burke at Bar Harbor, Maine in September 1923.
 Edna, who was divorced from Oscar Meech Burke, was the daughter of Edwin Sprague Marston, the former president and chairman of the board of directors of the Farmers' Loan & Trust Company (predecessor firm of Citigroup), and Emma Bennett (née Doty) Marston.
He had no children.
 He was an active member of the Freemasons.

He died on January 21, 1935 at his winter home in Santa Barbara, California, of a heart attack.
He was interred at Sleepy Hollow Cemetery in Sleepy Hollow, New York.
 After his death, his widow remarried to Archibald Gourley Thacher in 1937.
Beeckman was married first to Eleanor Thomas of Zanesville, Ohio in 1902.  She was the daughter of Gen. Samuel Russell Thomas and Ann Augusta (née Porter) Thomas and the sister of Edward Russell Thomas.  Upon her father's death in 1903, she inherited the income from half of his $10,000,000 estate. 
After his first wife's death in 1920, he remarried Edna (née Marston) Burke at Bar Harbor, Maine in September 1923.  Edna, who was divorced from Oscar Meech Burke, was the daughter of Edwin Sprague Marston, the former president and chairman of the board of directors of the Farmers' Loan & Trust Company (predecessor firm of Citigroup), and Emma Bennett (née Doty) Marston. He had no children.  He was an active member of the Freemasons.
He died on January 21, 1935 at his winter home in Santa Barbara, California, of a heart attack. He was interred at Sleepy Hollow Cemetery in Sleepy Hollow, New York.  After his death, his widow remarried to Archibald Gourley Thacher in 1937.
Robert Livingston Beeckman