He prepared for college at Phillips Academy, Andover, the gymnasium at Kornthal, Germany, and at the Rugby School in England.

In 1927, Schaff began a term as Lecturer in American Church History at Union Theological Seminary.

[1] Schaff wrote extensively in the area of church history and co-edited the Schaff-Herzog Encyclopedia.

He completed the unfinished work of his father, Philip, who had begun the History of the Christian Church before his death.

[2] David Schley Schaff played an early role in the introduction of and development of football in the United States.