R. L. Beeckman

Beeckman was the son of Gilbert Livingston Beeckman (1823–1874) and Margaret Atherton (née Foster) Beeckman (1832–1904). His sister, Katherine Livingston Beeckman, was married to Louis Lasher Lorillard, the son of Pierre Lorillard III, and another sister, Martha Beeckman, was married to New York banker Amos Tuck French. His family ancestry can be traced back to Dutch settlers of New Amsterdam dating to 1654. His ancestors include Robert Livingston the Elder, Declaration signer Philip Livingston and "The Chancellor" Robert Livingston.

His family owned the financial firm Lapsley Beeckman & Co. When Beeckman was young, his family moved to Newport, Rhode Island. He left school at the age of sixteen to become a stockbroker.

At the age of 16, Beeckman began his career at a stock brokerage firm in New York. At age 21, Beeckman became one of the youngest ever members of the New York Stock Exchange, being a member from 1887 until 1906. By 1916, he retired from the brokerage business. After this time, he was a member of the board of directors of several corporations, including the Industrial Trust Company, the Newport Trust Company, the International Silver Company, and the Newport Casino.

Beeckman was also a prominent polo player and tennis player. He played in the finals of the 1886 United States National Tennis Championships, which took place in Newport. He lost to defending champion Richard Sears with the score was 4–6, 6–1, 6–3, 6–4.

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 and it 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.