Clarence C. Zantzinger, son of Alfred and Sarah Crawford (Clark) Zantzinger, was born in Philadelphia, and, after private schooling in Germany, attended St. Paul's School in Concord, NH. He then gained his degree in civil engineering at Yale's Sheffield Scientific School in 1892 and his B.S. in Architecture at the University of Pennsylvania in 1895, but completed his architectural education with two years at the Ecole des Beaux-Arts in Paris, in the ateliers of Blondel
, receiving his diploma in 1901. After his return to Philadelphia, Zantzinger immediately established his own office and by 1902 was reporting independent commissions in the Philadelphia Real Estate Record and Builders' Guide
. By 1905 he and Charles L. Borie, Jr.
(another graduate of St. Paul's School) had launched the firm of Zantzinger & Borie
, with offices at 251 South 4th Street in Philadelphia. The partners were joined in 1910 by Milton B. Medary, Jr.
, and the firm name revised to Zantzinger, Borie & Medary
. Medary died unexpectedly in 1929, but the office name continued until at least 1932, reverting to Zantzinger & Borie after that point.
Zantzinger joined the AIA in 1903 and was made a fellow in 1911. He worked for many years on the AIA National Committee on Foreign Relations and Education; and, on the local level, he served as president of the Philadelphia Chapter. Zantzinger was, in addition, active in the T-Square Club, serving as director of its atelier and on its education committee. In 1917 Zantzinger was appointed by Pres. Woodrow Wilson to represent the United States on the War Trade Board in Sweden, and he was attached to the U.S. Legation in Stockholm. He further served on the National Capitol Parks and Planning Commission and in Phiadlephia as President of the City Parks Association.