He attended private schools and received an academic education at Harvard College, graduating A. B. in 1881. For two years (1881-3) he studied architecture at the Massachusetts Institute of Technology, and supplemented his early training in the office of Henry Hobson Richardson, remaining there until the latter's death in 1886.
To facilitate the task of completing the work in the office, Mr. Coolidge formed a partnership with two members of the drafting staff, George F. Shepley (see) and Frank E. Rutan (see), subsequently established practice under the firm name. One of their first commissions awarded in 1890 was for the campus plan and the first buildings at Leland Stanford Junior Uni¬versity at Palo Alto, Calif. Two years later they were chosen architects for the Ames Building in Boston, at the time of its completion the highest office building in the city, and on its top floor the firm opened its architectural office. Another early work in Boston was the old Chamber of Commerce built in 1892.
The firm’s most important achievements during the next few years were in Chicago. In 1892 commissioned to design the Art Institute, and the follow¬ing year the Public Library, Mr. Coolidge moved to Chicago to open an office there during the erection of the buildings. During that period the firm also designed the Shadyside Presbyterian Church in Pittsburgh. With the completion of the Art Institute in 1897 Mr. Coolidge returned to Boston, and in the increasingly busy years which ensued the firm carried on a wide and successful practice. Among its most important buildings were the New England Building erected at Cleveland, O., 1897; South Terminal Station, Boston, 1899 and the Back Bay Station in 1900; United States Building at the Paris Exposition, France, 1900; Stillman Infirmary, Harvard College, 1901; Chapel, Vassar College at Poughkeepsie, N. Y., 1902; the Library at Brown University, Providence, R. I., 1903; Harvard Medical School, Boston, 1903-07; and the Ryerson Public Library at Grand Rapids, Michigan.
Early in the century Mr. Coolidge won wide recognition in the field of college design. Under the firm name he prepared plans for buildings at Nebraska’s State University, the University of Kentucky, and at the University of Chicago, the Harper Memorial Library; Ida Noyes Hall, 1916; the Mitchell Tower group including Hutchinson Hall, Reynolds’ Student Club, and Marshall Assembly Hall, also the Law School, 1916. He was also associated with architect Charles A. Hodgdon of Chicago on Widebott Hall and the Social Research Building at the University, Swift Hall, the Joseph Bond Chapel and the Jones Chemical Laboratory.
In the period between 1914 and 1922 some years after the decease of both Shepley and Frank Rutan, Mr. Coolidge took George C. Shattuck into partnership, a draftsman in the office for a number of years. They were architects of Sprague Memorial Hall at Yale University, in 1917, and in 1922 Coolidge & Shattuck was awarded the Boston Society of Architects’ Medal of Honor on the Lying-in-Hospital as the most meritorious building erected in the city during that year. In 1917 Mr. Coolidge was sent to China by the Rockefeller Foundation to report on a site and prepare plans for a Hospital and Medical School for the China Medical Board at Peking and Shanghai. He also served as Consulting Architect in the buildings erected at Peking, and others at Constantinople for the College in the latter city.
In 1925 Mr. Coolidge organized a new firm, taking into partnership Henry R. Shepley, (son of his former associate), Francis V. Bulfinch and Lewis B. Abbott, and in this, the last phase of his career, was active until shortly before his death. During those years he was identified with the design of many outstanding buildings in the field of hospital design, the Lakeside Memorial Hospital at Cleveland; the Peter Brent Brigham Hospital, and units of the Massachusetts General Hospital in Boston; the Medical Center at Western Reserve University, Cleveland; Laboratories at the Rockefeller Institute of Medical Research at Princeton University and in New York; Medical School and Hospital group at Vanderbilt College, Nashville. Tenn., Children's and Infants’ Hospital in Boston, and the Hospital at Cornell’s Medical group in New York, completed in 1931.
At Harvard University, a number of distinguished buildings were erected from his plans, notably the new Law School, Freshman dormitories, the Collis Huntington Memorial Hospital, various units of the plan made possible by the Harkness gift, and new buildings in the campus yard. In 1906 when Harvard wished to honor its noted alumnus, it bestowed upon him a new degree, Doctor of Arts, to signalize his specific talents.
A long-time member and past president of the Boston Society of Architects, A. I. A., Mr. Coolidge was elected to Institute Fellowship in 1891, and later served two years on the A. I. A. Board of Directors. He was a figure of national prominence in the profession, a member and former Director of the American Federation of Arts, and at one time a Trustee of the American Academy at Rome, also held many public and honorary positions during his long career.