Archibald Cary Coolidge was born on March 06, 1866 in Boston, Massachusetts, United States. He was the son of Joseph Randolph and Julia (Gardner) Coolidge. He came of a family that included many names distinguished in the social and commercial life of Boston. His paternal grandmother was Eleonora Wayles Randolph, a grand-daughter of Thomas Jefferson. On his mother’s side was a strain of French Huguenot blood which added strength to the sturdy independence of the father’s Scotch-Irish inheritance.