Archibald Cary Coolidge (March 6, 1866 – January 14, 1928) was an American educator and diplomat. He was a professor of history at Harvard College from 1908 and the first director of the Harvard University Library from 1910 until his death. Coolidge was also a scholar in international affairs, a planner of the Widener Library, a member of the United States Foreign Service, and editor-in-chief of the policy journal Foreign Affairs. Early life Archibald Coolidge was born in Boston, Massachusetts as the third of five boys. His parents were Harvard University Law School graduate Joseph Randolph Coolidge and Julia (née Gardner) Coolidge, both from prominent and wealthy Boston Brahmin families. His siblings included U.S. Minister to Nicaragua John Gardner Coolidge, noted lawyer Harold Jefferson Coolidge Sr. (the father of zoologist Harold Jefferson Coolidge Jr.), architect J. Randolph Coolidge Jr. and mathematician and fellow Harvard professor Julian Lowell Coolidge. His paternal uncle was Thomas Jefferson Coolidge, the Boston businessman and U.S. Minister to France. His father, Joseph Randolph Coolidge, was a great-grandson of the 3rd United States President Thomas Jefferson, through his maternal great-grandparents, Thomas Mann Randolph Jr. and Martha Jefferson Randolph. Archibald's great-uncles were Thomas Jefferson Randolph, George Wythe Randolph, and his grandfather, Joseph Coolidge, was a distant relative of President Calvin Coolidge. Through his mother, Archibald was the nephew of John Lowell Gardner II. 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. Coolidge attended seven different elementary and preparatory schools, the Adams Academy in Quincy, and Harvard College, where he became associated with the Owl Club and graduated summa cum laude in history in 1887. He also attended the University of Berlin and the École des Sciences Politiques in Paris. He earned a Ph.D. from the University of Freiburg in Germany 1892. Career From 1893 on, he taught various history courses at Harvard, first as an instructor, from 1899 on as assistant professor, and in 1908, he was made a full professor of history. Coolidge today is recognized as having turned the Harvard College Library into a major research institution. Coolidge helped make the Harvard Library "one of the best organized libraries for scholars and students as well as one of the great libraries of the world." He is further credited with bringing the study of history of