His paternal uncle was Thomas Jefferson Coolidge, the Boston businessman and U.S. Minister to France.
His mother and uncle John were the grandchildren of merchant Joseph Peabody, one of the wealthiest men in the United States at the time of his death in 1844.
[6] Coolidge attended school in Boston before studying in Germany[1] and at Harvard University, where he was graduated in 1892, with an A.B.
[10] Together, they were the parents of two sons and a daughter: Harold Jefferson Coolidge Sr. died on July 31, 1934, and is buried at the Mount Auburn Cemetery in Cambridge, Massachusetts.
After his death, his widow remarried U.S. General and Chief of the Military Intelligence Division Sherman Miles (1882–1966) in 1954.